BILLABONG
billabong
(noun) a branch of a river made by water flowing from the main stream only when the water level is high
billabong
(noun) a stagnant pool of water in the bed of a stream that flows intermittently
Source: WordNet® 3.1
Etymology
Noun
billabong (plural billabongs)
(Australia) A stagnant pool of water.
A streambed that is only filled with water during the rainy season.
A channel that dead-ends which extends from the main part of a river.
(Australia, rare) An oxbow lake.
Source: Wiktionary
Bil"la*bong`, n. [Native name.]
Definition: In Australia, a blind channel leading out from a river; --
sometimes called an anabranch. This is the sense of the word as used
in the Public Works Department; but the term has also been locally
applied to mere back-waters forming stagnant pools and to certain
water channels arising from a source.
Source: Webster’s Unabridged Dictionary 1913 Edition