n.

1. 三人一組；三件一套；三合一
2. 【音】三和弦
3. 【化】三價元素；三價原子
4. 三部曲

n.

1. a group or set of three connected people or things.
   ▸a chord of three musical notes, consisting of a given note with the third and fifth above it.
   ▸a Welsh form of literary composition with an arrangement of subjects or statements in groups of three.
2. a Chinese secret society involved in organized crime.
   ▸a member of such a society.