- decay modes
- decayed knot
- deceleration force
- deceleration parachute
- decelerometer
- decentralized
- decentralized processing
- deceptive packaging
- decibel
- decimal digit
- decimal number
- decimal system
- decimatric wave
- deciphering
- decision
- decision criterion
- decision instruction
- decision tree
- deck span
- deck truss
- deck-chair
- deckhead
- decking
- declaration
- declarative
- declination angle
- decode-encode
- decoder circuit
- decoke
- decoloration
- decolorize
- decolourize
- decomposed ground
- decompression curve
- decompression table
- decontamination
- decorating kiln
- decorative paint
- decorticator
- decoupling filter
- decreasing function
- decree
- decrement counter
- decremeter
- decrepitation
- decryption
- decurrent
- dedicated
- dedicated memory
- deduce
- deductive theory
- deduster
- deep embankment
- deep fill
- deepened beam
- default button
- default context
- default reasoning
- defect annealing
- defence
- defensive
- deferred address
- deferred entry
- deferred income
- damming
- damming-up
- damp course
- damp ratio
- damp steam
- damp wood
- damp-proof
- damped oscillation
- damped wave
- dampener
- damper
- damper loss
- damping attenuation
- damping characteristics
- damping circuit
- damping coil
- damping constant
- damping factor
- damping force
- damping material
- damping period
- dampness
- dance
- dance hall
- dancers
- dancing seat
- danger
- danger area
- danger light
- danger point
- danger zone
- dangerous
- dangerous machine
- dangerous section
- dangling
- Daniell hygrometer