involuntary

adjective

UK /ɪnˈvɒləntri/

US /ɪnˈvɑːlənteri/

Something involuntary happens without you choosing or trying to do it.

Blinking is an involuntary action that happens without you thinking about it.

SYNONYMS

automatic reflexive unintentional instinctive spontaneous

RELATED WORDS

reflex automatic instinct involuntary muscle knee-jerk

OTHER MEANINGS

2. Done without conscious control, as when a body part moves on its own.

The doctor checked his involuntary movements during the exam.

3. Not done by choice or free will; forced or compelled.

She gave an involuntary gasp when she saw the surprise.

4. Happening by accident rather than on purpose.

His involuntary laugh during the quiet ceremony embarrassed him.