- detonics
- detour road
- detrital
- detrition
- detune
- deturn
- deuterium
- deuterohemophilia
- devastate
- developable surface
- devolve
- dew-point
- dewater
- dewatered sludge
- dewatering hole
- dexiben meter
- dextropropoxyphene
- diacritical mark
- diagnostic
- diagonal buttress
- diagonals pliers
- diagram stresses
- diakinesis
- dial backup
- dial gage
- dial indicator
- dial plate
- dial telephone
- dialed call
- dialing
- dialing tone
- dialling code
- dialog track
- dialuric acid
- dialysate
- dialysis
- diamagnetic material
- diameter
- diametric line
- diamond antenna
- diamond boring
- diamond count
- diamond pencil
- diamond saw
- diamond size
- diamond tool
- diamond-shaped
- diapason
- diaphragm pump
- diplex
- diplexer
- diplomacy
- dipmeter
- dipolar
- dipolar moment
- dipole
- dipole aerial
- dipole antenna
- dipole array
- dipole moment
- dipped
- dipped beam
- dipped electrode
- dipped headlight
- dipper
- dipper stick
- dipping
- dipping bed
- dipping method
- dipping process
- dipping sonar
- dipping varnish
- diproton
- dipstick
- dirac function
- direct access
- direct address
- direct addressing
- direct attach
- direct attachment
- direct broadcast
- direct calling
- direct channel
- direct code
- direct color
- direct communication
- direct component
- direct compression
- direct connect
- direct connection
- direct control
- direct cooling
- direct correlation
- Direct costs
- direct coupling
- direct current
- direct dial
- direct expenditures
- direct firing
- direct flow