Australian slang for physical labour. Usually heard in the phrase "hard yakka", meaning really hard physical labour.

The word is borrowed from the now-dead languages of the Jagera and Turrbal people who originally inhabited the Brisbane region. Its entry into spoken English probably dates from soon after European settlement of the area in 1824, via the already-common colonial practice of 'employing' natives for manual work. The 1898 Dictionary of Austral English has this to say:

Yakka, v. frequently used in Queensland bush-towns. "You yacka wood? Mine, give 'im tixpence;" - a sentence often uttered by housewives. It is given by the Rev. W. Ridley, in his 'Kamilaroi, and other Australian languages,' p 86. as the Turrubol (Brisbane) term for work, probably cognate with yugari, make, same dialect, and yengga, make, Kabi dialect, Queensland. It is used primarily for doing work of any kind, and only by English modification (due to 'hack') for cut. The spelling yacker is to be avoided, as the final r is not heard in the native pronunciation.

The Oxford English Dictionary records the use of "yacker" and "yakka" as a noun meaning "work" from 1888.

By the time of The Great Depression, such was the word's familiarity in the Australian vernacular that a Melbourne pyjama manufacturer, David K. Laidlaw, saw fit to adopt it as the brand name for his new line of overalls. The brand was spectacularly successful; Yakka workwear has been an iconic part of Australian culture ever since, hand-in-hand with stubbies and blue singlets. Yakka Pty Ltd bears much of the credit for the survival of "yakka" in Australian English, through its quintessentially Aussie advertising and the unkillable slogan, "There's nothing tougher than Hard Yakka." Even typing this, I'm haunted by a two-part basso profundo chorus of "Hard Yakka, Hard Yakka."

In modern usage, the word has retreated somewhat into self-conscious ockerism, used as often with irony as sincerity - victim of the same post-Paul Hogan cringe that has all but extinguished such glorious Strine as "chunder" and "bonzer". Quite a shame, because as words go, it's a little ripper.