1. 露底：grindstone 磨石砂轮 | grinning 露底 | grip chuck 套抓夹头

2. 咧嘴笑：;-( Fell like crying 想哭 | :-} Grinning 咧嘴笑 | :-) Happy 高兴

3. 露齿而笑的：pleased 满意的; | grinning 露齿而笑的; | smirking 傻笑的;

noun

1. a facial expression characterized by turning up the corners of the mouth
usually shows pleasure or amusement

Synonym: smilesmilinggrin