REM 
(rĕm)
(rĕm)n.
The twitching movements of the eye muscles and other physiological changes that occur during REM sleep.
[R(APID) E(YE) M(OVEMENT).]
- pyrometer
- pyrometric
- pyrometrical
- pyrometrically
- pyrometry
- pyromorphite
- pyronin
- pyronine
- pyrope
- pyrophoric
- pyrophosphate
- pyrophosphatic
- pyrophosphoric acid
- pyrophyllite
- pyrosis
- pyrostat
- pyrosulfate
- pyrosulfuric acid
- pyrotechnic
- pyrotechnical
- pyrotechnically
- pyrotechnics
- pyrotechny
- pyroxene
- pyroxenic