triplet
/ˈtrɪplɪt/noun
1
- （一般作triplets）one of three children or animals born at the same birth三胞胎中的一个。
2
- a set or succession of three similar things三个一组, 三件一套。
2.1
- Music a group of three equal notes to be performed in the time of two or four【乐】三连音符。
2.2
- a set of three rhyming lines of verse三行联句。
3
- Physics & Chemistry an atomic or molecular state characterized by two unpaired electrons with parallel spins【物理, 化】（原子或分子的）三重态（由两个平行旋转的不成对电子组成）。
3.1
- a group of three associated lines close together in a spectrum or electrophoretic gel三合光谱。
词源
mid 17th cent.: from TRIPLE, on the pattern of doublet.