yawning reflex呵欠反射
yawning gulf开口很大的鸿沟;口子很大的鸿沟
Past yawning打哈欠
Frequent Yawning数欠
help yawning帮助打哈欠
While Yawning而打哈欠
yawning wearily疲惫地打呵欠;打哈欠的疲劳
yawning moment方向力矩
Yawning Fissure豁口裂缝
V-I（不及物动词） If you yawn, you open your mouth very wide and breathe in more air than usual, often when you are tired or when you are not interested in something. 打哈欠
She yawned, and stretched lazily.
她打了个哈欠，伸了个懒腰。
N-COUNT（可数名词） Yawn is also a noun. 哈欠
Rosanna stifled a huge yawn.
罗莎娜忍住了一个大哈欠。