Australian slang for afternoon — part of a distinctive linguistic pattern where Aussies add -o to abbreviated words, turning everyday vocabulary into something unmistakably local.
Arvo is how Australians say afternoon, and it's more than just a shortcut. It's part of a systematic linguistic pattern where Australians add the -o suffix to abbreviated words: smoko (smoke break), garbo (garbage collector), journo (journalist), ambo (ambulance officer), servo (service station). The pattern existed in British English but Australians adopted it wholesale, making it a distinctive marker of Australian identity.
The word emerged around 1920 in Tasmania, documented in Green's Dictionary of Slang. The transformation from afternoon to arvo follows Australian phonetics: the 'f' becomes voiced, and the 'ar' reflects the non-rhotic (r-less) pronunciation characteristic of Australian accents.
Using arvo signals casual familiarity — you'd say it to mates and colleagues, not in formal writing. It's not slang in the sense of being edgy or youth-specific; it's just how Australians talk when they're being themselves.