Boon wurrung was a dialect of Wuy-wurrung, a Kulin language of the Pama-Nyungan language family. The ethnonym occasionally used in early writings to refer to the Bunwurrung, namely Bunwurru, is derived from the word bu:n, meaning "no" and wur:u, signifying either "lip" or "speech".
The Boon wurrung are predominantly a saltwater people whose lands, waters and cosmos encompassed some 3,000 square miles (7,800 km2) of territory around Western Port Bay and the Mornington Peninsula. It western boundary was set at Werribee. To the southeast it extended from Mordialloc through to Anderson Inlet, as far as Wilson's Promontory. Inland its borders reached the Dandenong Ranges, and ran eastwards as far as the vicinity of Warragul.
Communities consisted of six or more (depending on the extent of the territory) land-owning groups called clans that spoke a related language and were connected through cultural and mutual interests, totems, trading initiatives and marriage ties. Access to land and resources, such as the Birrarung, by other clans, was sometimes restricted depending on the state of the resource in question. For example; if a river or creek had been fished regularly throughout the fishing season and fish supplies were down, fishing was limited or stopped entirely by the clan who owned that resource until fish were given a chance to recover. During this time other resources were utilised for food. This ensured the sustained use of the resources available to them. As with most other Kulin territories, penalties such as spearings were enforced upon trespassers. Today, traditional clan locations, language groups and borders are no longer in use and descendants of Wurundjeri people live within modern day society.
It is generally considered that before European settlement, six separate clans existed, each with an arweet, or clan headman.