1. 锋利的　(of the points and cutting edges of knives, etc.) sharp
2. 热衷的，热心的，渴望（做某事）的　(of a person) having a strong, active interest in sth; eager to do sth
3. 激烈的，紧张的　(of a competition or struggle) done with eagerness and activity on both sides
4. 良好的；敏锐的，敏捷的　(of mind, feelings, senses, etc.) good, strong, quick at understanding, etc.

　～ edge　锋利的刀刃
　～ interest　强烈的兴趣
　～ to pass the examination　渴望通过考试
　～ to visit that city　很想去参观那个城市
　～ about going to the picnic　希望去野餐
　～ about〔on〕 music　爱好音乐
　～ of hearing　听力敏锐

　This flower has got a keen scent.　这花有一种刺鼻的气味。
　Mary is a keen critic.　玛丽是一个尖刻的批评家。
　She is a keen reader of my novels.　她是我的小说的热心读者。
　She has a keen mind.　她头脑机敏。
　This knife is very keen.　这把小刀非常锋利。
　The north wind is keen and biting.　北风刺骨。
　Her father wants her to go to university, but she is not keen.　她父亲想让她上大学，但她并不想去。
　The competition for the first prize was keen.　争夺第一名的竞争很激烈。
　She is really keen about the trip.　她渴望去旅行。
　He is so keen about his game as to forget everything else.　他这么专心致志于做游戏，以至把其他一切都忘了。
　He is keen after moneymaking.　他一心想赚钱。
　He is not very keen on jazz.　他对爵士音乐不太感兴趣。
　My daughter is keen of hearing.　我的女儿听觉灵敏。
　The boy is keen to go to sea.　这孩子很想去航海。
　He's keen to pass the examination.　他热切希望能够通过考试。
　Father is keen for my brother to study law.　父亲很希望我兄弟学法律。
　The parents were keen that their daughter should become musician.　父母渴望他们的女儿成为音乐家。

 ♣ keen, acute, sharp
　参见sharp条。
 ♣ keen, eager
　这两个词都可表示“渴望”。keen着重指极大的兴趣引起的渴望；eager指巨大的热情所产生的渴望，有时表示急不可耐的心情。

　［同义词］ acid, biting, fierce, intent, shrewd, wise
　［反义词］ apathetic, blunt, dull
　［词源］中古英语hene<古英语cene（锋利）