overact

verb (used with or without object)

1. to act in an exaggerated manner.

verb

1. to act or behave in an exaggerated manner, as in a theatrical productionAlso: overplay

v.1610s, “to go too far in action,” from over- + act (v.). Meaning “to play a part with too much emphasis, to chew the scenery” is from 1630s. Related: Overacted; overacting.