N-COUNT. 透支；透支额. If you have an overdraft, you have spent more money than you have in your bank account, and so you are in debt to the bank.

Buying an expensive car involved him in debt.

买一辆昂贵的汽车使他负债累累。

※Better go to bed supperless than rise in debt. 宁可饿肚子，切莫去借债。