playact vs mime

playact is not a noun while mime is a noun.

Word	Noun	Adjective	Verb	Adverb
playact	No	No	Yes	No
mime	Yes	No	Yes	No

As verbs, mime is a hyponym of playact; that is, mime is a word with a more specific, narrower meaning than playact:

Other hyponyms of playact include stooge, pantomime, ham, ham it up, overact, overplay, underact, underplay.

playact (noun)	mime (noun)
	a performance using gestures and body movements without words
	an actor who communicates entirely by gesture and facial expression

playact (verb)	mime (verb)
perform on a stage or theater	act out without words but with gestures and bodily movements only
	imitate (a person or manner), especially for satirical effect