- diagonal slating
- diameter
- diamond saw
- diaphragm arch
- diaphragm pump
- diploma
- dipper relay
- dipper tooth
- dipping varnish
- dipteral
- direct coupling
- direct drive
- direct expansion
- direct extrusion
- direct glaze
- direct heating
- direct impact
- direct lighting
- direct radiation
- direct ratio
- direct reading
- direct sound
- direct steam
- direct stress
- direct talon
- Direct taxes
- direct toward
- direct wave
- direction beacon
- direction coupler
- direction key
- direction line
- direction measurement
- diatomaceous brick
- diatomaceous soil
- diatomite powder
- diazo printer
- dictatorial
- diesel hammer
- diesel shovel
- differential pressure
- differential settlement
- difficult
- diffluence coefficient
- diffused lighting
- diffuser
- diffusion block
- diffusion burner
- diffusion coefficient
- diffusion field
- diffusion glass
- diffusion pattern
- diffusive
- dig pit
- digest
- digging angle
- digging bar
- digging chain
- digging speed
- digging though
- digging wheel
- digital computer
- digital indicator
- digital information
- digital pattern
- directional characteristic
- directive time
- directly measured
- director curve
- directory window
- dirt bailer
- dirt mover
- dirt pocket
- dirty
- disable
- disappearance
- disassemble
- disassembly operation
- disaster
- disastrous
- disband
- disbelieve
- disc crusher
- disc pig
- disc saw
- disc screen
- disc valve
- discharge channel
- discharge duct
- discharge electrode
- discharge flue
- discharge height
- discharge lamp
- discharge rod
- discharge section
- discharge trough
- discharge tube
- discharge tunnel
- discharge valve
- discharging cart