a black sheep
英[ə blæk ʃi:p]美[e blæk ʃip]
n.
败家子，败类，害群之马; 败群之马
害群之马; 败类; 害群之马
1
He is really a black sheep of the family.
是啊，他可真是个败家子。
2
Sheila ran off with a married man, but then she always has been the black sheep of the family.
希拉同一个有妇之夫私奔了，但是从此他永远成了家庭中的败类。
