yawn /jɔ:n/ I. vi. 打呵欠：yawn one’s head off 不断打呵欠；make a person yawn 使人疲倦，使人困 ‖II. n. ［c］呵欠：suppress a yawn 止住呵欠 He gave a yawn and then fell asleep. 他打了个呵欠，然后就睡着了。