n.(用单匹马拉车时使用的)车前横木
Patients went singly into the consulting room.
病人一个接一个地进入诊疗室。
The stamps are available singly or in books of ten.
邮票有单枚的,也有十枚一册的。
They marched out singly or in pairs.
他们一个一个地或成双成对地走出来。