- dichromatic
- dielectric field
- dielectric gas
- dielectric liquid
- dielectric test
- diesel cycle
- diethyl ether
- differentiable
- differential comparator
- differential coupler
- differential selsyn
- diffracted beam
- diffraction grating
- diffraction zone
- diffusate
- diffuse line
- diffuse ray
- diffuser cone
- diffusion constant
- diffusion flux
- diffusion pump
- digitized chamber
- dilatometer
- dilution factor
- dimension measurement
- dimensional crossover
- dimensional formula
- dimethyl ether
- diode clamp
- diode coupling
- diopter
- dioptric power
- dip gauge
- dip plating
- dip pole
- depression
- derivate action
- desiccant charge
- design head
- desired pressure
- desired value
- desuperheated gas
- detune
- deuterium
- dial key
- dialing
- dialing tone
- dialysis
- diameter equalization
- diamond winding
- diplex
- diplex reception
- dipole polarization
- dipole radiation
- dipole relaxation
- dipole susceptibility
- diproton
- dirac function
- direct
- direct cooling
- direct current
- direct evaporation
- direct feed
- direct injection
- direct motion
- direct route
- direct suspension
- direct-reaction
- direct-viewing
- directed ray
- direction
- direction gauge
- dielectric ellipsoid
- dielectric hysteresis
- dielectric susceptibility
- differential capacitor
- differential delay
- differential method
- differential topology
- differential voltmeter
- differential windlass
- differentiation operator
- differientiability
- diffracted
- diffracted ray
- diffuse radiation
- diffused water
- diffuser grille
- diffusible
- diffusion area
- diffusion heat
- diffusion resistance
- digit rate
- digital
- digital communication
- digital controller
- digital modem
- digital recording
- digital transducer
- digital transmission