咧嘴而笑用英文怎么说

"咧嘴而笑"用英语可以翻译为"grin"或"smirk"。

"Grin"是一个动词，指的是露出开心、高兴或满意的笑容。例如：

He couldn't help but grin when he heard the good news. (他听到好消息时禁不住咧嘴笑了起来。)
She grinned from ear to ear when she saw her birthday present. (她看到生日礼物时咧嘴笑得耳朵都竖起来了。)

"Smirk"也是一个动词，指的是带着自满或戏谑的笑容。例如：

He smirked when he saw the look on her face. (他看到她的表情时带着自满的笑容。)
She couldn't help but smirk at the ridiculous comment. (她看到那条荒谬的评论时忍不住咧嘴笑了起来。)

两个词都来自中世纪英语"grinnen"，意思是"笑"或"咧嘴笑"。在现代英语中，"grin"和"smirk"的用法略有不同，但都表示咧嘴笑的意思。