| G081 | GPR | Ground Penetrating Radar | Uses electromagnetic waves to detect objects, changes in material, and voids beneath the surface | Locating underground utilities before excavation |
| G082 | GRC | Glass Reinforced Concrete | Concrete reinforced with glass fibers for improved strength and durability | Prefabricated façade panels in building construction |
| G083 | GRF | Glass Reinforced Fabric | Fabric strengthened with glass fibers for enhanced tensile properties | Aerospace composite material in aircraft interiors |
| G084 | GRI | Gas Research Institute | Organization focused on innovation in gas technology and utilization | Developing efficient natural gas combustion systems |
| G085 | GRIN | Gradient Index | Optical element with a gradual change in refractive index to bend light precisely | GRIN lenses in fiber optic communications |
| G086 | GRM | Geometric Road Model | Digital representation of road geometry for simulation and design | Used in highway alignment and safety studies |
| G087 | GRO | Gas Recovery Operation | Capturing and utilizing waste gas to improve efficiency | Flare gas recovery in oil refineries |
| G088 | GRP | Glass Reinforced Plastic | Plastic composite reinforced with glass fibers for high strength-to-weight ratio | Boat hull and water tank manufacturing |
| G089 | GRR | Gage Repeatability and Reproducibility | Method to analyze variation in measurement systems | Dimensional inspection in machining processes |
| G090 | GRS | Ground Resisting Structure | Structure that resists soil or earth pressure | Reinforced concrete retaining wall design |
| G091 | GRT | Gross Registered Tonnage | Measurement of a ship’s internal volume capacity | Shipping industry cargo capacity records |
| G092 | GRV | Ground Reference Velocity | Velocity of an object relative to the Earth’s surface | Aircraft navigation and speed control |
| G093 | GS | Galvanized Steel | Steel coated with zinc for corrosion resistance | Outdoor roofing sheets and structural members |
| G094 | GSA | General Services Administration | U.S. agency handling procurement, property management, and logistics | Federal office building operations |
| G095 | GSC | Gear Shift Control | Mechanism that enables selection of transmission gears | Manual transmission shifter in cars |
| G096 | GSD | Ground Sample Distance | Distance between pixel centers in remote sensing images | Satellite imaging resolution measurement |
| G097 | GSE | Ground Support Equipment | Equipment used to service aircraft between flights | Baggage loaders and tow tractors at airports |
| G098 | GSF | Gross Square Feet | Total area measurement including all floors of a building | Commercial real estate property valuation |
| G099 | GSI | Geosynthetic Institute | Organization supporting research and standards in geosynthetics | Guidelines for geotextile use in road construction |
| G100 | GSM | Grams per Square Meter | Unit to measure weight and density of fabrics and paper | Evaluating textile quality in apparel manufacturing |
| G101 | GSP | Grounding System Plan | Plan outlining the electrical grounding design for safety | Factory electrical installation blueprints |
| G102 | GSR | Galvanic Skin Response | Change in electrical conductance of the skin | Stress measurement devices |
| G103 | GST | Goods and Services Tax | Value-added tax levied on goods and services | Pricing calculation in manufacturing supply chains |
| G104 | GSU | Generator Step-Up | Transformer increasing voltage from generator output to grid level | Power plant transmission system |
| G105 | GT | Gas Turbine | Engine converting gas combustion into mechanical power | Jet aircraft propulsion systems |
| G106 | GTA | Gas Tungsten Arc | Welding process using tungsten electrode and inert gas shield | TIG welding stainless steel |
| G107 | GTB | Gas Turbine Blade | Blade designed to extract energy from hot gases in a turbine | Aircraft engine hot section |
| G108 | GTC | General Terms and Conditions | Standard contract clauses in engineering projects | Procurement contracts for plant machinery |
| G109 | GTD | Gear Tooth Design | Specification of gear tooth profile for performance | Helical gear manufacturing drawings |
| G110 | GTE | Gas Turbine Engine | Combustion-based engine producing high thrust and power | Helicopter propulsion units |
| G111 | GTI | Gas Technology Institute | Research body advancing gas utilization technologies | Development of low-NOx burners |
| G112 | GTL | Gas to Liquids | Process converting natural gas into liquid hydrocarbons | Synthetic diesel production plants |
| G113 | GTM | Geometric Tolerance Measurement | Measuring geometric accuracy of manufactured parts | Coordinate measuring machine (CMM) inspection |
| G114 | GTO | Gate Turn-Off Thyristor | Semiconductor device that can be turned off by gate signal | Power control in electric locomotives |
| G115 | GTP | Gas Turbine Power | Power output capacity of a gas turbine system | Electrical generation plant rating |
| G116 | GTR | Gear Tooth Ratio | Ratio between the number of teeth on meshing gears | Speed control in gearboxes |
| G117 | GTS | Gas Turbine Shaft | Main rotating shaft transferring turbine power | Marine gas turbine propulsion |
| G118 | GTW | Gross Train Weight | Total weight of a train including cargo and locomotive | Freight train load calculation |
| G119 | GU | Gauge Unit | Standardized measurement for wire diameter or thickness | Electrical cable sizing charts |
| G120 | GUR | Guaranteed Ultimate Recovery | Estimated total hydrocarbon recovery from a reservoir | Oil field production forecasting |
| G121 | GV | Gate Valve | Valve controlling flow by lifting a gate out of the fluid path | Pipeline isolation in oil and gas |
| G122 | GVA | Gross Value Added | Measure of economic productivity | National manufacturing productivity analysis |
| G123 | GVC | Global Value Chain | Sequence of processes involved in manufacturing globally | Automotive parts supply network |
| G124 | GVD | Group Velocity Dispersion | Pulse broadening effect in optical fibers | High-speed internet fiber optics design |
| G125 | GVI | General Visual Inspection | Basic inspection method to check visible conditions | Aircraft fuselage checks |
| G126 | GVM | Gross Vehicle Mass | Maximum permissible loaded vehicle weight | Truckload compliance check |
| G127 | GVP | Good Ventilation Practice | Standards ensuring adequate airflow in facilities | HVAC system installation |
| G128 | GVR | Gas Volume Reduction | Process of reducing gas volume through compression | LNG production stages |
| G129 | GVS | Gravity Ventilation System | Ventilation using natural convection and buoyancy | Factory roof vent design |
| G130 | GVW | Gross Vehicle Weight | Weight of a vehicle plus cargo and passengers | Weighbridge measurement for trucks |
| G131 | GW | Groundwater | Water located beneath the Earth’s surface | Hydrological engineering and well design |
| G132 | GWP | Global Warming Potential | Measure of how much heat a greenhouse gas traps | Climate impact analysis of refrigerants |
| G133 | GWPS | Groundwater Protection System | Measures to prevent contamination of groundwater | Landfill lining design |
| G134 | GWR | Guided Wave Radar | Radar level measurement using guided microwaves | Oil tank level sensors |
| G135 | GWS | Groundwater System | Network of aquifers and flow patterns | Environmental engineering studies |
| G136 | GX | Gas Exchange | Process of swapping gases in a system | Engine combustion chamber operation |
| G137 | GXL | Gasoline Extra Load | Type of automotive electrical cable | Vehicle wiring harnesses |
| G138 | GY | Grey Cast Iron | Cast iron containing graphite flakes for machinability | Engine block casting |
| G139 | GZ | Metacentric Height | Stability measure of a floating body | Ship stability calculations |
| G140 | GZN | Galvanized Zinc | Zinc-coated steel for corrosion protection | Electrical cable trays |
| G141 | GZP | Galvanized Pipe | Steel pipe coated with zinc to resist rust | Plumbing in industrial facilities |
| G142 | GZT | Galvanized Trough | Zinc-coated cable support tray | Electrical wiring infrastructure |
| G143 | GZR | Gear Zero Reference | Alignment reference for gear installation | Industrial gearbox assembly |
| G144 | GZV | Gas Zone Valve | Valve controlling gas supply in zones | Laboratory gas distribution systems |
| G145 | GZZ | Ground Zero Zone | Origin point of a measurement or blast radius | Blast analysis in demolition engineering |
| G146 | G1 | First Gear Ratio | Initial low-speed gear in transmissions | Manual car gear selection |
| G147 | G2 | Second Gear Ratio | Intermediate gear ratio in transmissions | Truck gear shifting |
| G148 | G3 | Third Gear Ratio | Higher gear for speed increase | Motorcycle gear operation |
| G149 | G4 | Fourth Gear Ratio | Gear for efficient cruising | Highway driving fuel economy |
| G150 | G5 | Fifth Gear Ratio | High-speed overdrive gear | Passenger car fuel efficiency |
| G151 | G6 | Sixth Gear Ratio | High-speed fuel-efficient gear | Modern manual transmission cars |
| G152 | GAe | Gasoline Aero Engine | Aircraft piston engine running on gasoline | Small airplane propulsion |
| G153 | GMM | Geometric Mean Method | Statistical method for averaging ratios | Quality control in batch testing |
| G154 | GRH | Gear Reduction Hub | Hub reducing rotational speed and increasing torque | Heavy-duty machinery drives |
| G155 | GWSR | Groundwater Source Recharge | Process of replenishing aquifers | Managed aquifer recharge systems |
| G156 | GES | Geothermal Energy System | System harnessing Earth’s heat for power | Geothermal power plants |
| G157 | GPSA | Gas Processors Suppliers Association | Industry body for gas processing standards | Setting LNG industry guidelines |
| G158 | GEV | Ground Effect Vehicle | Vehicle designed to operate using ground effect lift | Hovercraft design |
| G159 | GMW | Global Manufacturing Way | Standardized manufacturing process model | Automotive plant process guidelines |
| G160 | GQMS | Global Quality Management System | International framework for quality | Aerospace component certification |
| G161 | GRSB | Gear Reduction Spur Bearing | Bearing for supporting spur gear reduction systems | Gearbox assembly in conveyors |
| G162 | GHD | Gear Housing Design | Structural design of gear housings | Automotive differential casing |
| G163 | GHS | Globally Harmonized System | International hazard classification system | Chemical labeling in industry |
| G164 | GHT | Gear Heat Treatment | Heat-treating gears for hardness and durability | Induction hardening of gear teeth |
| G165 | GIM | Gas Injection Molding | Injection molding process using gas to form hollow parts | Automotive plastic fuel tanks |
| G166 | GVAh | Gigavolt-Ampere hour | Unit of electrical energy | Large-scale power plant energy accounting |
| G167 | GNP | Gross National Product | Total value of goods and services produced by a country | Economic output analysis |
| G168 | GPD | Gallons Per Day | Flow rate measure in water systems | Municipal water plant output |
| G169 | GPH | Gallons Per Hour | Flow rate measurement for liquids | Aircraft fuel consumption rate |
| G170 | GPM | Gallons Per Minute | Liquid flow rate measurement | Fire pump performance rating |
| G171 | GPDV | Gas Pressure Differential Valve | Valve controlling flow based on pressure difference | Gas distribution networks |
| G172 | GFG | Gas-Fired Generator | Electrical generator powered by gas combustion | Standby power for factories |
| G173 | GFC | Ground Fault Circuit | Circuit path causing unintended current flow to ground | Electrical fault detection |
| G174 | GFD | Gas Flow Detector | Sensor measuring gas movement | Natural gas leak monitoring |
| G175 | GFI | Ground Fault Interrupter | Device that shuts off power when leakage is detected | Bathroom electrical outlets |
| G176 | GFRP | Glass Fiber Reinforced Polymer | Composite material for high strength and low weight | Bridge deck panels |
| G177 | GHP | Ground Heat Pump | Heat pump system using stable ground temperature | Energy-efficient building heating |
| G178 | GME | Gas Mixing Equipment | Devices blending gases to desired ratios | Welding gas mixer units |
| G179 | GHSR | Gear Hub Speed Reducer | Reducer for controlling gear output speed | Conveyor drive systems |
| G180 | GHL | Gear Head Lathe | Lathe with integrated geared headstock | Precision metal turning |
| G181 | GTF | Gear Tooth Form | Specific shape profile of gear teeth | Involute profile for spur gears |
| G182 | GQF | Gear Quality Factor | Measure of precision in gear manufacturing | High-performance transmission gears |
| G183 | GYH | Gear Yaw Housing | Gear housing allowing angular alignment | Wind turbine yaw system |
| G184 | GWB | Gear Wheel Bearing | Bearing supporting rotating gear wheels | Large industrial press drive |
| G185 | GIC | Grounding Isolation Circuit | Circuit providing electrical grounding isolation | Sensitive electronics protection |
| G186 | GOG | Gas Oil Generator | Generator running on gas oil fuel | Offshore platform power generation |
| G187 | GDL | Gas Diffusion Layer | Layer in fuel cells allowing gas distribution | PEM fuel cell stack design |
| G188 | GOR | Gas Oil Ratio | Ratio of gas to oil produced from a well | Petroleum production analysis |
| G189 | GOC | Gas Oil Contact | Interface level between gas and oil phases in a reservoir | Reservoir engineering studies |
| G190 | GSV | Gross Sales Volume | Total revenue from sales before deductions | Annual manufacturing company reports |
| G191 | GID | Gas Insulated Device | Electrical device with gas insulation for compactness | Gas-insulated switchgear in substations |
| G192 | GICL | Gas Injection Control Line | Tubing delivering gas for reservoir injection | Oil well enhanced recovery systems |
| G193 | GNR | Gas Nitriding | Heat treatment adding nitrogen to steel surface | Wear-resistant gear manufacturing |
| G194 | GFCI | Ground Fault Circuit Interrupter | Device cutting power during leakage | Construction site electrical safety |
| G195 | GRTD | Gas Return Temperature Differential | Difference between gas return and supply temperatures | HVAC performance monitoring |
| G196 | GTCM | Gas Turbine Control Module | Module controlling turbine parameters | Power plant turbine control system |
| G197 | GFFR | Gas Fired Furnace | Furnace heated by natural gas combustion | Industrial forging shop heating |
| G198 | GMB | Gas Mixing Blender | Equipment blending different gases for process use | Industrial oxygen-nitrogen mixer |
| G199 | GPP | Gas Processing Plant | Facility treating natural gas for distribution | LNG terminal processing facility |
| G200 | GNS | Gas Network System | Interconnected gas pipelines and facilities | National gas distribution grid |
