(rapid eye movement)
* (rare) rem
From the initial letters of rapid eye movement.
rapid eye movement
* REM sleep
Shortened from remaining.
remaining time: In music, the time remaining in a track.
Shortened from remark.
(computing) A programming language statement used for documentation (in BASIC for example); also used in DOS batch files.
Shortened from rare earth metal.
(chemistry) rare earth metal(s).