dire - drif
- direct broadcast
- direct cell
- direct circulation
- direct crosswind
- direct current
- direct detection
- direct insertion
- direct lighting
- direct method
- direct mode
- direct picture
- direct product
- direct read-out ground station
- direct read-out image dissector
- direct read-out infrared radiometer
- direct reading instrument
- direct route
- direct solar radiation
- direct sound wave
- direct tide
- direct transmission system
- direct-reading thermometer
- direct-vision nephoscope
- direct-vision prism
- direction
- direction finder
- direction finding
- direction of movement
- directional absorptivity
- directional emissivity
- directional gain
- directional shear
- directional spectrum
- directivity
- directivity factor
- directivity function
- director
- Dirichlet boundary condition
- dirigible balloon ascent
- discharge
