Where "Zac" Comes From
"Zac" was Australian slang for a sixpenny coin, first recorded in the 1890s. The most frequently proposed origin is a connection to the Scottish pronunciation of "sixpence" — "saxpence" — though this etymology has not been confirmed by documentary evidence. The word was in general use throughout the late 19th and early 20th century, when sixpence was a coin of real practical value: enough for a meal, a tram fare, or a beer.
Decimalisation on 14 February 1966 replaced the Australian pound with the Australian dollar, converting sixpence to five cents — a coin too small to carry the old name. "Zac" largely disappeared from active monetary use after that date, though it survives in expressions like "not a zac" (meaning penniless) and "I wouldn't give a zac for it" (meaning worthless). The word's obsolescence is precise: it ended not because people stopped using it but because the coin it named ceased to exist.
Source: Wikipedia — “Zac (coin)”
"That old car isn't worth a zac these days."
How Aussies Actually Use It
These days almost nobody uses "zac" to mean an actual amount of money — it survives almost entirely in the fixed phrase "not worth a zac," describing something of little or no value.
It's a nostalgic bit of slang, most often used by older Australians, though the phrase itself is still widely understood across generations.
🎓 Want to sound like a true Aussie?
Watch Down Under English on YouTube for real Australian pronunciation, slang lessons, and culture — taught by an Australian educator.
Watch on YouTube →