writhe
verb
Writhe means to twist and turn your body, usually because of pain or discomfort. It's like if you get a stomachache and you feel like you need to squirm and move around.
Example
1. The snake writhed in agony after being bitten by the spider.
2. I could feel my muscles writhe with exhaustion after the long run.
3. The audience writhed in laughter after hearing the comedian's joke.