unin - user
- uninsulated wire
- unintelligible crosstalk
- uninterruptible power supply
- unit
- unit composition
- unit element
- unit of brightness
- unit of measurement
- unit pulse
- unit vector
- unite several telephone channels
- united automatic communication system user
- unity
- universal receiver
- universal time
- unlimited rotary mechanism
- unloaded
- unloaded cavity
- unloaded circuit
- unloaded quality
- unloaded reserve
- unlocked flip-flop
- unlocking
- unmanned
- unmanned balloon
- unmanned vehicle
- unmodulated carrier
- unmodulated oscillation
- unmodulated subcarrier
- unnumbered
- unnumbered acknowledgement
- unnumbered message
- unobstructed path
- unpackaged microcircuit
- unpolarized
- unpolarized light
- unrecorded cassette
- unrecoverable vehicle
- unregulated
- unregulated power supply
