N-COUNT 极瘦弱的人;无家可归者;流浪儿 If you refer to a child or young woman as a waif, you mean that they are very thin and look as if they have nowhere to live. 极瘦弱的人;无家可归者;流浪儿
...a dirty-faced waif of some five or six years.
五六岁大、脸上脏兮兮的流浪儿
The director wants a waif-like, teenage girl with long, dark hair for the role.