1PHRASAL VERB-ERG (因大笑、劇痛等)(使)彎腰,(使)弓身 If something doubles you up, or if you double up, you bend your body quickly or violently, for example because you are laughing a lot or because you are feeling a lot of pain. (因大笑、劇痛等)(使)彎腰,(使)弓身
...a savage blow in the crutch which doubled him up. [VERB noun PREP.]
對他下身兇狠的一擊疼得他直不起腰
They laugh so hard they double up with laughter. [VP + with/in]