A Billabong of the Goulburn, Victoria: a 1884 painting by Henry James Johnstone | Painting: Henry James Johnstone/Creative Commons

Surfers will instantly recognize it as the iconic Australian surf brand founded in 1973 by Gordon Merchant. But, where does the name "billabong" come from?

According to etymologists - the historians who study the origin and the evolution of the words and their multiple meanings - there are two disputed sources for the origin of the term "billabong."

Nevertheless, the most reliable evidence yet is that the word derives from the Wiradjuri expression "bilaban," i.e., the creek or watercourse that runs only during and after the rain or rainy season.

The Wiradjuri are a group of indigenous Australian Aboriginal people that live in central New South Wales. The language scientists stress that "billa" means "river," and "bong" or "bung" means "dead."

There's also a theory that supports the idea that the word "billabong" is of Scottish Gaelic background.

Today, a billabong is an Australian noun that designates a branch of a river, an isolated stagnant pond, or dead-end channel created by water flowing from the main stream during a flood, or left behind after a river changes course.

Other English native speakers will refer to this natural phenomenon as an oxbow lake or backwater.

These "dead rivers," or pools of still water, reflect a common circumstance in the Australian landscape - an arid climate punctuated and surrounded by more or less persistent bodies of water.

The truth is that the surf company honored its roots and came up with a brand name truly inspired in the Australian culture. Even if, ironically, a billabong is a flat water surface that doesn't produce any waves.