o ‧ ver ‧ act /ˌəʊvərˈækt $ ˌoʊ-/ BrE AmE verb [intransitive]
[ Word Family: noun : ↑ act , ↑ action ≠ ↑ inaction , ↑ activity ≠ ↑ inactivity , ↑ reaction , ↑ interaction , ↑ overacting ; adjective : ↑ acting , ↑ active ≠ ↑ inactive ; verb : ↑ act ≠ ↑ overact ; adverb : ↑ actively ]
to act in a play with too much emotion or movement – used to show disapproval
—overacting noun [uncountable]