a curved piece of metal, plastic or wire for hanging things on, catching fish with, etc. 钩；钓钩；挂钩；鱼钩 
a picture/curtain/coat hook 挂图钩；窗帘钩；挂衣钩 a fish hook 鱼钩 Hang your towel on the hook. 把你的毛巾挂在钩上。 The key was hanging from a hook. 钥匙挂在钩子上。 Your coat’s hanging on a hook behind the door. 你的外套挂在门后的挂钩上。
(in boxing 拳击运动 a short hard hit that is made with the elbow bent 钩拳 
a left hook to the jaw 击向下颌的一记左钩拳
(in cricket and golf 板球及高尔夫球 a way of hitting the ball so that it curves to the side instead of going straight ahead (usually by mistake in golf, but deliberately in cricket) 曲线球 a thing that is used to make people interested in something 吸引人的事物；诱饵 The images are used as a hook to get children interested in science. 这些图像用以吸引孩子们对科学产生兴趣。 Well-chosen quotations can serve as a hook to catch the reader’s interest. 精心选择的引语可以吸引读者的兴趣。
Word OriginOld English hōc, of Germanic origin; related to Dutch hoek ‘corner, angle, projecting piece of land’, also to German Haken ‘hook’.
Idioms
by hook or by crook
using any method you can, even a dishonest one 想方设法；不择手段
hook, line and sinker
off the hook
having got free from a difficult situation or a punishment （使）摆脱困境，逃避惩罚 I lied to get him off the hook. 为了让他摆脱麻烦我撒了谎。 No way will she let you off the hook this time. 这次她绝不会放过你。 I was finally off the hook. 我终于摆脱了困境。
- (becoming old-fashioned)
if you leave or take a landline phone off the hook, you take the receiver (= the part that you pick up) off the place where it usually rests, so that nobody can call you （为防止电话打进来而使听筒）不挂上
on the hook for something
- (North American English, informal)
responsible for paying for something 钩子： 负责支付某些东西Citizens are increasingly on the hook for more of their own medical costs. 公民们越来越多地为自己的医疗费用买单。
ring off the hook
sling your hook
- (British English, informal)
(used especially in orders 尤用于命令 to go away 走开；滚蛋