败家子的英语翻译是“spendthrift”，意思是指一个人花钱不讲究，花钱如流水。来源是英文“spend”（花费）和“thrift”（节俭）的组合。例句：

He's a spendthrift, always spending money on expensive clothes and cars. 他是个败家子，总是花大钱买昂贵的衣服和汽车。

My husband is a spendthrift and I always have to keep an eye on our bank account. 我丈夫是个败家子，我总是得盯着我们的银行账户。

Her parents were spendthrifts and they ended up bankrupt. 她的父母是败家子，最后他们破产了。