paradoxical sleep vs REM sleep

paradoxical sleep and REM sleep both are nouns.

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

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

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

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

paradoxical sleep (noun)	REM 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