n.

1. 结合（体）；联合（体）[U][C]
   The combination of the 50 states forms the United States of America.

   五十个州结为一体组成了美利坚合众国。

2. （有共同目的的）团体；联盟[C]
   The farmers are forming a combination to market their goods at fair prices.

   农场主结成联盟，以便用合理的价格销售货物。

3. 连衫裤[P]
4. （打开密码锁的）对号密码；密码锁
   He had forgotten the combination of the safe.

   他忘记了保险箱密码。

5. 【数】组合[C]
6. 【化】化合

n.

1. the action of combining different things.
2. a union in which the component elements are individually distinct.
3. Mathematics  a group of things chosen from a larger number without regard to their arrangement.
4. a sequence of numbers or letters used to open a combination lock.
5. (combinations) dated a single undergarment covering the body and legs.