yawn

1. V-I 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。

2. N-COUNT Yawn is also a noun. 哈欠

Rosanna stifled a huge yawn. 罗莎娜忍住了一个大哈欠。