underact \| ̷ ̷ ̷ ̷| ̷ ̷\verb Etymology:under (I) + act transitive verb 1.: to perform (a dramatic part) with less than the requisite skill or vigor 2.: to perform with restraint for greater dramatic impact or personal force intransitive verb : to perform feebly or with restraint < the rest of the cast knew how to underact for the greatest small-screen effectiveness — Saul Carson >