Synonyms of involuntary

1 Syllable

gut, blind

2 Syllables

reflex, unmeant, guter, will-less, knee-jerk, grudging, forced

3 Syllables

spontaneous, instinctual, unbidden, habitual, natural, unwitting, unthinking, reluctant, unconscious, uncheerful, unwilled, hot-and-cold, begrudging, unprompted, unwilling

4 Syllables

unintended, perfunctory, intuitional, impulsive, compulsory, unreflecting, automatic, mechanical, undesigned, instinctive, reflexive, conditioned, unobliging, uncontrolled, mandatory, intuitive

5 Syllables

second-nature, unpremediated, compulsatory, obligatory, unintentional, uncalculated, matter-of-course, machine-driven, autogenetic, unmeditated

6 Syllables

unpremeditated, undeliberate, unaccommodating