thumb

1. N-COUNT Your hand has four fingers and one thumb. 大拇指

She bit the tip of her left thumb, not looking at me. 她咬着左手的大拇指头，也不看我。

2. V-T If you thumb a lift or thumb a ride, you stand by the side of the road holding out your thumb until a driver stops and gives you a lift. (站在公路边) 竖起大拇指请求 (搭便车)

It may interest you to know that a boy answering Rory's description thumbed a ride to San Antonio. 可能让你感兴趣的是，有个和罗里描述相符的男孩竖起大拇指请求搭便车到圣安东尼奥。

3. PHRASE If you are under someone's thumb, you are under their control, or very heavily influenced by them. 在…的控制下; 深受…的影响

I cannot tell you what pain I feel when I see how much my mother is under my father's thumb. 我无法向你形容，当我看到母亲完全在父亲的控制之下时我有多么痛苦。

4. green fingers→see green

5. rule of thumb→see rule