- [countable]
any of the joints in the fingers, especially those connecting the fingers to the rest of the hand 指节；指关节 
She clenched the phone till her knuckles were white. 她紧握电话，连指关节都变白了。
Oxford Collocations Dictionaryadjective- bare
- bleeding
- bloodied
- …
- crack
- bruise
- graze
- …
- bone
- rap somebody on the knuckles
- rap somebody over the knuckles
- (also hock)[uncountable, countable]
a piece of meat from the lower part of an animal’s leg, especially a pig （猪等动物的）肘，蹄 knuckle of pork 猪蹄
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Word OriginMiddle English knokel (originally denoting the rounded shape when a joint such as the elbow or knee is bent), from Middle Low German, Middle Dutch knökel, diminutive of knoke ‘bone’. In the mid 18th cent. the verb knuckle (down) expressed setting the knuckles down to throw the taw (large marble) in a game of marbles, hence the notion of applying oneself with concentration.
Idioms
near the knuckle
- (British English, informal)
(of a remark, joke, etc. 言语、玩笑等 connected with sex in a way that is likely to offend people or make them feel embarrassed 近乎下流；近乎猥亵 His act is too near the knuckle for me. 他的表演对我来说太接近尾声了。
(give somebody/get) a rap on/over/across the knuckles
rap somebody on/over the knuckles | rap somebody’s knuckles
- (informal)
to criticize somebody for something 批评；指责 The company was rapped over the knuckles for broadcasting the interview. 该公司因播出采访而受到严厉批评。 She was rapped over the knuckles by her boss for criticizing the company in the press. 她因为在报刊上批评公司而受到了老板的斥责。