Rapid 504 Absolutely Essential Words Lesson 27
/ˈræp.ɪd/ (adj)
fast and quick, swift, speedy, prompt, precipitous, hurried, hasty, sudden, nimble, rash, expeditious, express, brisk, fleet
REM stands for rapid eye movement. During REM sleep, your eyes move around rapidly in a range of directions, but don’t send any visual information to your brain. That doesn’t happen during non-REM sleep.
Source: https://www.webmd.com/
Antonym: slow
Noun: rapidity
Adverb: rapidly
