前俯后仰

Pinyin: qián fǔ hòu yǎng Explanation: 身体前后晃动。形容大笑或困倦得直不起腰的样子。 Thesaurus:  set one's eyes at flow, convulsions, guffaw, Hung Tang cachinnation, horselaugh, sad Hesitate life, hold one's sides, laughing uncontrollably