overdraft
noun [ C ]
uk/ˈəʊvədrɑːft/ us/ˈəʊvərˌdræft/ (also bank overdraft) BANKING
an amount of money that a customer with a bank account is temporarily allowed to owe to the bank, or the agreement which allows this:
run up/have an overdraft Research shows that 58% of students have an overdraft.
I paid off my overdraft as soon as I got my pay cheque.
We have an overdraft facility of £500 with our bank.
an overdraft fee/rate/charge
a free/interest-free overdraft