a piece of iron that attracts objects made of iron towards it, either naturally or because of an electric current that is passed through it 磁铁；磁石；吸铁石 
Oxford Collocations Dictionaryadjective- powerful
- strong
- bar
- …
- act as
- act like
- attract something
- magnet for
- [usually singular] magnet (for somebody/something)
a person, place or thing that somebody/something is attracted to 有吸引力的人（或地方、事物） In the 1990s the area became a magnet for new investment. 这个地区在 20 世纪 90 年代成了新的投资热点。 The scent of flowers acts as a magnet to bees. 花的香味像磁石一样吸引着蜜蜂。
Oxford Collocations Dictionaryadjective- powerful
- strong
- bar
- …
- act as
- act like
- attract something
- magnet for
an object with a magnetic surface that you can stick onto a metal surface 磁体；磁性物体 fridge magnets of your favourite cartoon characters 你最喜欢的动画人物冰箱贴
Oxford Collocations Dictionaryadjective- powerful
- strong
- bar
- …
- act as
- act like
- attract something
- magnet for
Word Originlate Middle English (denoting lodestone): from Latin magnes, magnet-, from Greek magnēs lithos ‘lodestone’, probably influenced by Anglo-Norman French magnete (from Latin magnes, magnet-).