stage business vs playacting

stage business and playacting both are nouns.

Word	Noun	Adjective	Verb	Adverb
stage business	Yes	No	No	No
playacting	Yes	No	No	No

As nouns, playacting is a hypernym of stage business; that is, playacting is a word with a broader meaning than stage business:

stage business: incidental activity performed by an actor for dramatic effect
playacting: the performance of a part or role in a drama

Other hypernyms of stage business include acting, performing, playing.

stage business (noun)	playacting (noun)
incidental activity performed by an actor for dramatic effect	the performance of a part or role in a drama