1.
If you make an ~ movement or exclamation, you make it suddenly and without intending to because you are unable to control yourself.
Another surge of pain in my ankle caused me to give an ~ shudder.
ADJ
involuntarily
His left eyelid twitched involuntarily.
ADV: ADV with v
2.
You use ~ to describe an action or situation which is forced on someone.
...insurance policies that cover ~ unemployment...
= forced
ADJ