| G051 | GCI | Galvanic Corrosion Inhibitor | A material or coating that prevents corrosion caused by contact between dissimilar metals. | Zinc coatings on steel to prevent rust. |
| G052 | GCP | Ground Control Point | A reference point on the ground used in surveying and mapping to ensure accuracy. | Used in drone mapping for construction projects. |
| G053 | GCS | Gas Control System | A system that manages the flow, pressure, and safety of gas in an industrial setting. | Regulating natural gas in a refinery. |
| G054 | GD&T | Geometric Dimensioning and Tolerancing | A symbolic language for defining allowable variation in size, form, and position in manufacturing. | Specifying hole positions on a machined plate. |
| G055 | GDI | Gasoline Direct Injection | Fuel injection system where gasoline is directly injected into the combustion chamber. | Modern car engines for improved efficiency. |
| G056 | GDL | Gas Diffusion Layer | Layer in fuel cells allowing gases to reach the catalyst while removing water. | PEM fuel cells in electric vehicles. |
| G057 | GDP | Gas Discharge Plasma | Plasma generated by electrical discharge in gases. | Used in neon lighting. |
| G058 | GDR | Gauge Data Recorder | Device used to record gauge readings over time. | Monitoring pressure in a boiler. |
| G059 | GDS | Gas Distribution System | Infrastructure for transporting and delivering gas to end-users. | City natural gas supply pipelines. |
| G060 | GE | Gas Engine | An engine that uses natural gas or other gases as fuel. | Industrial power generation with gas engines. |
| G061 | GEA | Gas Engine Alternator | Alternator coupled with a gas-powered engine to generate electricity. | Standby power systems. |
| G062 | GEC | Ground Earth Clamp | A clamp used to connect electrical equipment to earth for grounding. | Welding machine grounding clamp. |
| G063 | GEG | Gas Engine Generator | Generator driven by a gas-powered engine. | Hospital backup generators. |
| G064 | GEL | Gel Electrophoresis | Laboratory technique for separating molecules based on size and charge. | DNA analysis in biomedical labs. |
| G065 | GEM | Gas Emission Monitoring | Process of measuring gases emitted from a process or equipment. | Monitoring CO₂ emissions in power plants. |
| G066 | GEO | Geothermal Energy | Heat energy extracted from the earth’s core for use. | Geothermal power plants. |
| G067 | GEP | Gas Expansion Process | Process of expanding compressed gas to produce work or cooling. | LNG regasification facilities. |
| G068 | GER | Gear | A toothed wheel that transmits motion and force to another gear. | Gearbox in a motorcycle. |
| G069 | GES | Grounding Electrode System | Electrical grounding setup to protect equipment and personnel. | Building electrical grounding system. |
| G070 | GF | Glass Fiber | Fine fibers made from glass used for insulation and reinforcement. | Fiberglass boat construction. |
| G071 | GFCI | Ground Fault Circuit Interrupter | Device that shuts off electricity when a ground fault is detected. | Bathroom electrical outlets. |
| G072 | GFE | Ground Fault Equipment | Protective equipment against ground faults. | Industrial power distribution boards. |
| G073 | GFRP | Glass Fiber Reinforced Polymer | Composite material made of a polymer matrix reinforced with glass fibers. | Aircraft panels and wind turbine blades. |
| G074 | GFS | Gas Flow Sensor | Device measuring the flow rate of gas in a system. | Medical oxygen delivery systems. |
| G075 | GG | Gas Generator | Equipment that produces gas for various applications. | Gas turbine generators in power plants. |
| G076 | GGB | Grease Gun Bearing | A bearing that receives lubrication from a grease gun. | Maintenance of industrial machinery. |
| G077 | GGI | Gas Gathering Infrastructure | System for collecting natural gas from multiple wells. | Oil and gas production fields. |
| G078 | GGM | Gas Generation Module | Unit producing gas for industrial processes. | Hydrogen production in a lab. |
| G079 | GGS | Gas Gathering Station | Facility collecting and processing natural gas. | Natural gas field processing plant. |
| G080 | GH | Greenhouse | Structure with controlled environment for plant growth. | Agricultural crop production. |
| G081 | GHI | Global Horizontal Irradiance | Total solar radiation received per unit area by a horizontal surface. | Solar panel efficiency studies. |
| G082 | GHP | Ground Heat Pump | Heating and cooling system using earth’s thermal energy. | Residential geothermal HVAC. |
| G083 | GHS | Globally Harmonized System | International system for chemical hazard classification and labeling. | Safety Data Sheets (SDS). |
| G084 | GI | Galvanized Iron | Iron coated with zinc for corrosion resistance. | Water pipes in plumbing. |
| G085 | GID | Gas Injection Device | Equipment that injects gas into a process stream. | Gas lift in oil wells. |
| G086 | GIF | Graphics Interchange Format | A bitmap image format supporting animation. | Engineering presentation animations. |
| G087 | GIG | Gas Insulated Gear | Electrical switchgear insulated with gas like SF₆. | High-voltage substations. |
| G088 | GIL | Gas Insulated Line | Power transmission line insulated with SF₆ gas. | Urban underground high-voltage power systems. |
| G089 | GIM | Gas Injection Molding | Plastic molding using gas-assisted technology. | Automotive interior panels. |
| G090 | GIP | Gas Injection Process | Industrial process of injecting gas for reaction or displacement. | Enhanced oil recovery. |
| G091 | GIS | Gas Insulated Switchgear | Compact switchgear using gas insulation. | Electrical substations. |
| G092 | GIT | Gas Insulated Transformer | Transformer insulated with non-flammable gas. | Indoor electrical substations. |
| G093 | GJ | Gigajoule | Unit of energy equal to one billion joules. | Measuring industrial energy use. |
| G094 | GK | Gate Keeper | Device or person that controls access to a facility. | Factory security gate system. |
| G095 | GL | Ground Level | The base level of a site relative to reference points. | Building foundation design. |
| G096 | GLA | Gas Lift Assembly | Equipment for injecting gas into a well to lift fluids. | Oil production enhancement. |
| G097 | GLB | Global | Worldwide or universal application. | Global engineering standards. |
| G098 | GLC | Glass-Lined Column | Chemical process column lined with glass for corrosion resistance. | Pharmaceutical reactor column. |
| G099 | GLE | Glass Lined Equipment | Process equipment lined with glass to resist corrosion. | Acid-resistant reactors. |
| G100 | GLM | Gas Leak Monitor | Device for detecting gas leaks. | LPG cylinder storage safety. |
| G101 | GLO | Gas Lift Operation | Method of artificial lift in oil wells using gas injection. | Deep oil well production. |
| G102 | GLP | Gas Liquefaction Plant | Facility where gas is cooled to liquid form. | LNG export terminals. |
| G103 | GLS | Ground Light System | Lighting system installed at or near ground level. | Airport runway lights. |
| G104 | GLT | Glass Lined Tank | Storage tank lined with glass for corrosion protection. | Storing corrosive chemicals. |
| G105 | GM | General Manager | Person responsible for overall operations of an organization. | Factory GM overseeing production. |
| G106 | GMA | Gas Metal Arc | Welding process using a continuous wire electrode and shielding gas. | MIG welding of steel. |
| G107 | GMC | Geometrical Mean Concentration | Statistical measure for concentrations. | Air pollution analysis. |
| G108 | GMD | Gas Metering Device | Equipment measuring the amount of gas consumed. | Residential gas meters. |
| G109 | GMF | Gas Mixing Facility | Facility mixing different gases to achieve desired composition. | Specialty gas production. |
| G110 | GMG | Gas Mixing Generator | Equipment generating mixed gases for processes. | Welding gas mixtures. |
| G111 | GMI | Gas Measurement Instrument | Tools used to measure gas parameters. | Portable gas analyzers. |
| G112 | GML | Gas Metering Line | Piping system for gas measurement. | Industrial gas distribution. |
| G113 | GMM | Gas Mixing Module | Modular system for blending gases. | Laboratory gas supply. |
| G114 | GMS | Gas Management System | Computerized system to monitor and control gas usage. | Oil refinery gas optimization. |
| G115 | GMT | Greenwich Mean Time | The mean solar time at the Prime Meridian. | Coordinating international engineering projects. |
| G116 | GMV | Gas Metering Valve | Valve controlling gas flow for measurement. | Gas chromatograph feed control. |
| G117 | GN | Ground Nut | Fastener nut connected to an earth ground. | Electrical ground connection. |
| G118 | GNC | Gas Network Controller | Control system for managing gas distribution. | National gas pipeline system. |
| G119 | GND | Ground | Reference point in an electrical circuit. | Circuit grounding in PCB design. |
| G120 | GNJ | Ground Joint | Pipe joint allowing rotation while maintaining seal. | Fire hydrant connections. |
| G121 | GNL | Gas Natural Licuado | Spanish term for liquefied natural gas (LNG). | LNG shipping industry. |
| G122 | GNP | Gross National Product | Economic measure of production. | Country’s annual output calculation. |
| G123 | GNS | Gas Network System | Infrastructure for distributing gas. | Municipal gas supply grid. |
| G124 | GO | Gas Oil | Middle distillate fuel derived from petroleum. | Diesel fuel for generators. |
| G125 | GOC | Gas Oil Condensate | Hydrocarbon liquid from natural gas production. | Offshore oil platforms. |
| G126 | GOD | Gas Oil Distillate | Fuel oil fraction obtained from crude oil. | Industrial boilers. |
| G127 | GOI | Gas Oil Injection | Injecting oil for lubrication or production. | Engine lubrication systems. |
| G128 | GOL | Gas Oil Line | Pipeline carrying gas oil. | Power plant fuel supply. |
| G129 | GOP | Gas Oil Pump | Pump for transferring gas oil. | Fuel handling in refineries. |
| G130 | GOS | Gas Oil Separator | Device separating oil from gas in production. | Oilfield processing units. |
| G131 | GOT | Gas Oil Tank | Storage tank for gas oil. | Fuel depots. |
| G132 | GP | Gauge Pressure | Pressure measured relative to atmospheric pressure. | Boiler pressure gauges. |
| G133 | GPA | Gas Processing Agreement | Contract for processing natural gas. | Gas plant operations. |
| G134 | GPC | Gas Processing Complex | Facility for processing natural gas. | Petrochemical gas processing plants. |
| G135 | GPD | Gallons Per Day | Unit of water or fluid flow rate. | Water treatment plant output. |
| G136 | GPF | Gas Particulate Filter | Filter removing particulates from exhaust gases. | Diesel engines with GPF. |
| G137 | GPG | Gas Pressure Gauge | Device for measuring gas pressure. | Oxygen cylinder pressure gauge. |
| G138 | GPI | Gas Pressure Indicator | Instrument showing gas pressure readings. | LPG storage tanks. |
| G139 | GPL | Gas Processing Line | Pipeline carrying gas for processing. | Petrochemical facilities. |
| G140 | GPM | Gallons Per Minute | Unit of fluid flow rate. | Pump capacity measurement. |
| G141 | GPN | Gas Processing Network | Network of facilities processing natural gas. | LNG and petrochemical plants. |
| G142 | GPP | Gas Processing Plant | Facility refining raw natural gas. | Onshore gas processing facility. |
| G143 | GPS | Global Positioning System | Satellite-based navigation system. | Surveying construction sites. |
| G144 | GPU | Gas Processing Unit | Unit operation in gas processing. | Gas dehydration unit. |
| G145 | GPV | Gas Pressure Valve | Valve regulating gas pressure. | Industrial furnace gas control. |
| G146 | GQ | Gauge Quality | Standard measure of gauge accuracy. | Quality control in metrology labs. |
| G147 | GR | Gear Ratio | Relationship between the number of teeth in two meshing gears. | Bicycle gear settings. |
| G148 | GRA | Gas Recovery Apparatus | Equipment for recovering gas from a process. | Refrigeration gas recovery tools. |
| G149 | GRB | Gas Recovery Bag | Flexible container for storing recovered gas. | Laboratory gas collection. |
| G150 | GRC | Glass Reinforced Concrete | Concrete with glass fiber for added strength. | Architectural panels. |
| G151 | GRD | Ground | Earthing point in electrical systems. | Electrical installation grounding. |
| G152 | GRF | Gas Recovery Facility | Facility recovering gases for reuse. | Carbon capture plants. |
| G153 | GRG | Gas Recovery Generator | Device generating power from recovered gas. | Landfill gas-to-energy projects. |
| G154 | GRI | Gas Recovery Installation | Industrial setup for gas recovery. | Oilfield flare gas recovery. |
| G155 | GRL | Ground Level | Height reference at the site. | Civil engineering surveys. |
| G156 | GRM | Gas Recovery Module | Portable module for gas recovery. | Mobile flare gas recovery units. |
| G157 | GRO | Gas Recovery Operation | Process of collecting and reusing gases. | Biogas plant operations. |
| G158 | GRP | Glass Reinforced Plastic | Plastic strengthened with glass fibers. | Boat hulls and chemical tanks. |
| G159 | GRS | Gas Recovery System | System designed for capturing and reusing gases. | Industrial CO₂ recovery. |
| G160 | GRT | Gross Registered Tonnage | Measure of a ship’s size. | Cargo ship classification. |
| G161 | GRU | Gas Recovery Unit | Equipment recovering gas from processes. | LNG boil-off gas recovery. |
| G162 | GRV | Gas Relief Valve | Valve for releasing excess gas pressure. | Storage tank safety. |
| G163 | GS | Gas Separator | Device separating gas from other materials. | Oil-gas separation units. |
| G164 | GSC | Gas Scrubber | Equipment removing impurities from gas streams. | Flue gas desulfurization. |
| G165 | GSD | Gas Shutoff Device | Device for stopping gas flow. | Emergency shutoff in gas pipelines. |
| G166 | GSE | Ground Support Equipment | Tools supporting aircraft maintenance. | Baggage tractors at airports. |
| G167 | GSF | Gas Supply Facility | Facility delivering gas to customers. | LNG distribution hubs. |
| G168 | GSG | Gas Storage Gage | Gauge measuring gas storage levels. | LPG bulk tanks. |
| G169 | GSI | Gas Supply Installation | Infrastructure for supplying gas. | Industrial gas distribution. |
| G170 | GSL | Gas Supply Line | Piping delivering gas to a user. | Kitchen gas pipelines. |
| G171 | GSM | Global System for Mobile Communications | Mobile phone standard. | Industrial IoT applications. |
| G172 | GSN | Gas Supply Network | Network for delivering gas. | City natural gas grid. |
| G173 | GSP | Gas Supply Pump | Pump moving gas through a system. | Cryogenic gas systems. |
| G174 | GSR | Gas Supply Regulator | Device controlling gas delivery pressure. | Residential LPG regulators. |
| G175 | GSS | Gas Storage System | Infrastructure for storing gases. | LNG tank farms. |
| G176 | GST | Goods and Services Tax | Indirect tax on goods and services. | Engineering service contracts. |
| G177 | GSU | Gas Supply Unit | Unit delivering gas to a process. | Welding gas supply skid. |
| G178 | GSV | Gas Storage Vessel | Pressure vessel storing gas. | Compressed air tanks. |
| G179 | GT | Gas Turbine | Engine producing power from expanding gases. | Jet engines in aircraft. |
| G180 | GTA | Gas Turbine Assembly | Assembly of a gas turbine engine. | Power plant turbines. |
| G181 | GTB | Gas Turbine Blade | Blade inside a turbine converting gas energy to motion. | Aircraft jet engines. |
| G182 | GTC | Gas Turbine Compressor | Compressor feeding air into a turbine. | Industrial gas turbines. |
| G183 | GTD | Gas Turbine Drive | Mechanical drive using gas turbines. | Ship propulsion systems. |
| G184 | GTE | Gas Turbine Engine | Engine powered by expanding gases. | Military fighter jets. |
| G185 | GTF | Gas Turbine Fuel | Fuel used for gas turbine engines. | Aviation kerosene. |
| G186 | GTG | Gas Turbine Generator | Generator driven by a gas turbine. | Combined cycle power plants. |
| G187 | GTI | Gas Turbine Installation | Industrial setup of gas turbines. | Offshore oil platform power. |
| G188 | GTJ | Gas Turbine Jet | Jet engine powered by gas turbine technology. | Commercial airliners. |
| G189 | GTL | Gas to Liquids | Technology converting natural gas to liquid fuels. | GTL diesel production. |
| G190 | GTM | Gas Turbine Module | Modular gas turbine assembly. | Portable power units. |
| G191 | GTN | Gas Turbine Nozzle | Nozzle directing flow in a turbine. | Turbofan engines. |
| G192 | GTO | Gas Turbine Output | Power generated by a gas turbine. | Electricity output measurement. |
| G193 | GTP | Gas Turbine Plant | Facility housing gas turbine generators. | Peak load power stations. |
| G194 | GTR | Gas Turbine Rotor | Rotor in a gas turbine engine. | Industrial turbine maintenance. |
| G195 | GTS | Gas Turbine System | Complete system of a gas turbine engine. | Power generation systems. |
| G196 | GTT | Gas Turbine Technology | Technology used in turbine development. | Jet engine R&D. |
| G197 | GTU | Gas Turbine Unit | Standalone turbine system. | Offshore platform generators. |
| G198 | GTV | Gas Turbine Valve | Valve controlling fuel or air in turbines. | Turbine fuel control systems. |
| G199 | GU | Gas Utilization | Use of gas for industrial, commercial, or domestic purposes. | Natural gas heating systems. |
| G200 | GUV | Gas Utilization Value | Efficiency metric for gas use. | Evaluating power plant efficiency. |
