REM sleep vs paradoxical sleep

REM sleep and paradoxical sleep both are nouns.

Word	Noun	Adjective	Verb	Adverb
REM sleep	Yes	No	No	No
paradoxical sleep	Yes	No	No	No

As nouns, REM sleep and paradoxical sleep are synonyms defined as:

REM sleep and paradoxical sleep: a recurring sleep state during which dreaming occurs; a state of rapidly shifting eye movements during sleep

Other synonyms of REM sleep include rapid eye movement, rapid eye movement sleep, REM.

REM sleep (noun)	paradoxical sleep (noun)
a recurring sleep state during which dreaming occurs; a state of rapidly shifting eye movements during sleep	a recurring sleep state during which dreaming occurs; a state of rapidly shifting eye movements during sleep