Entry 1 sense Webster, 1913 Involuntarily /ĭnˌ-vōl-ŭn'-tẽr-ĭlˌ-ē/ · In·vol·un·ta·ri·ly · IPA /ɪnˌvɑlənˈtɛɹɪli/ 01 adv. In an involuntary manner; not voluntarily; not intentionally or willingly. 1. In an involuntary manner; not voluntarily; not intentionally or willingly.