grin from ear to ear
US /ɡrɪn frəm ɪr tu ɪr/
UK /ɡrɪn frəm ɪr tu ɪr/

1.
咧嘴大笑, 笑得合不拢嘴
to smile broadly, showing great pleasure or amusement
:
•
When she saw the surprise party, she started to grin from ear to ear.
当她看到惊喜派对时,她开始咧嘴大笑。
•
He was grinning from ear to ear after winning the lottery.
中彩票后,他咧嘴大笑。