Entry 1 sense Webster, 1913 Actuator /ăk'-tyo͞o-ātˌ-ẽr/ · Ac·tu·a·tor · IPA /ˈæk.t͡ʃu.eɪ.tɚ/ 01 n. One who actuates, or puts into action. 1. One who actuates, or puts into action.[R.]