In Australian English, a billabong (/ˈbɪləbɒŋ/ BIL-ə-bong) is a small body of water, usually permanent. It is usually an oxbow lake caused by a change in course of a river or creek, but other types of small lakes, ponds or waterholes are also called billabongs. The term is likely borrowed from Wiradjuri, an Aboriginal Australian language of New South Wales.