Real Dictionary

refund
countable noun: A refund is a sum of money which is returned to you, for example because you have paid too much or because you have returned goods to a shop.
verb: If someone refunds your money, they return it to you, for example because you have paid too much or because you have returned goods to a shop.

refund in Accounting
verb: If someone refunds your money, they return what you have paid them.

refund in American English 1
the act of refunding or the amount refunded; repayment
to give back or pay back (money, etc.); repay
intransitive verb: to make repayment
noun: an act or instance of refunding
transitive verb: to give back or restore (esp. money); repay

refund in American English 2
to fund again or anew
transitive verb: to fund anew

refund in British English
noun: return of money to a purchaser or the amount so returned
verb: to give back (money), as when an article purchased is unsatisfactory

refund in Retail 1
verb: If someone refunds your money, they return what you have paid them.

refund in Retail 2
noun: When you are given a refund, the money you have paid for something is returned to you.