- glucose
- gold-plated
- glycol cooler
- gnomoprojection
- gnomostereo projection
- Goldhaber triangle
- go channel
- goniometric locator
- gram-roentgen
- gramme winding
- granular desiccant
- granular ice
- granulated cork
- granulation
- graphic instrument
- graphical panel
- graphical symbol
- graphite bush
- graphite resistor
- Grashof number
- grasshopper fuse
- grating spectroscope
- Gratz number
- governor
- grading
- grading shield
- gradual
- gradual condensation
- Graetz number
- gram-equivalent
- gravisphere
- gravitational interaction
- gravitational lens
- gravitational potential
- gravitational radiation
- gravitational wave
- gravity circulation
- gravity feed
- graybody
- grazing
- grid
- grille area
- gravity flow
- gravity recirculation
- gravity ventilator
- gray
- grazing collision
- green
- grenz ray
- grey
- grey scale
- grid bias
- grid fill
- grid gas
- grid packing
- ground cable
- ground conductivity
- ground detector
- ground impedance
- ground outlet
- ground plate
- ground resistance
- ground rod
- ground system
- grounding reactor
- growth
- Guillemin effect
- Gunn amplifier
- gyrator filter
- gyrofrequency
- gyromagnetic material
- gyromagnetics
- H drive
- H plane
- H wave
- grid battery
- grid coil
- grid substation
- grid system
- ground indicator
- ground lug
- ground plane
- ground protection
- ground recharge
- ground return
- grounded system
- group delay
- growing crystal
- growing rate
- guidance
- guide vane
- guide wave
- guiding center
- Gunn diode
- gyromagnetic couple
- gyromagnetic radius
- H bend
- H theorem
- hadron
- hair