1. done without conscious control or intention
2. done against one's will; compulsory

Examples

• She gave an involuntary shiver when the cold wind hit her.
• Breathing is an involuntary bodily function.
• His involuntary muscle spasms were caused by stress.
• The patient showed involuntary eye movements during the examination.
• Many refugees faced involuntary relocation during the war.
• The company announced involuntary layoffs due to budget cuts.
• He let out an involuntary gasp of surprise.