What does flatty mean?
"Flatty" is an informal noun used mainly in Australia and New Zealand to describe a flat tyre — one that has lost its air through a puncture or leak, leaving it deflated against the road. The word is a colloquial derivative of "flat," softened with the friendly -y ending typical of Australasian speech, so a driver might say they "got a flatty" or had to stop and "change a flatty" rather than using the more formal phrase "flat tyre." A secondary, looser use treats a flatty as a flat-heeled, flat-soled shoe, though this meaning is less widespread. Because the term is casual and regionally rooted, visitors from Britain or North America may not recognise it immediately, but within its home territory it is a natural part of everyday motoring talk. It carries no negative connotation beyond the inconvenience of a puncture itself.
Informal term for a flat or punctured tyre.
"The ute was sitting noticeably low at the back thanks to a slow-leaking flatty."
Common in Australian and New Zealand everyday speech; less familiar in Britain and North America.
Informal term for a flat-soled shoe without a heel.
"She packed a pair of flatties for sightseeing around the city."
Standard pluralisation with -ies; used both for multiple flat tyres and multiple flat shoes.
"Both trailers in the convoy had suffered flatties on the corrugated road."
In Australia and New Zealand, a punctured tyre isn't just 'flat' — it's a flatty.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of flatty
"Flatty" is formed by adding the familiar English suffix -y to "flat," an adjective that entered Middle English from Old Norse "flatr" during the medieval period of Norse influence on English. The suffix -y routinely produces affectionate or informal nouns from adjectives, which is how the deflated-tyre sense arose in colloquial use. The word took strongest root in Australian and New Zealand English, where such compact, casual derivatives are especially common; it is therefore a native English formation rather than a borrowing, with cognates limited to other words built on the same Norse-derived adjective "flat."
How flatty is actually used
"Flatty" is casual and conversational rather than formal; it is most firmly established in everyday speech in Australia and New Zealand, where it commonly replaces "flat tyre." Outside those regions it may be unfamiliar or read as slang. As with many -y derivatives, it has a light-hearted, colloquial feel.
Easily confused with flatty
"Flat" (or "flat tire") is the standard term for a deflated tyre in British and American English, while "flatty" is an informal, chiefly Australasian variant of the same idea.