What it means
In Australia, thongs are flip-flops, plain and simple. Rubber slip-on sandals, beach-approved, servo-approved, somehow even pub-approved if nobody's feeling fancy. If you're from somewhere else, the word can sound a bit chaotic because it means underwear there, but in Aussie English it's all about what goes on your feet. Bonus local drama: if the sole flicks your heel, that's the classic thong slap.
Usage examples
"It's 35 degrees, so I grabbed the esky, chucked on my thongs, and ducked to the servo for ice before the barbie."
"Don't forget your thongs for the beach, the sand gets way too hot by midday."
"He wore thongs to a fancy dinner and nobody batted an eyelid, that's Australia for you."
"I rocked up in thongs and sunnies, and Mum still said I was overdressed for the arvo."
"One of my thongs blew out halfway across the car park, so I had to do that sad little barefoot shuffle."
Where it comes from
In this sense, thong comes from an older English word for a narrow strip of leather or fastening strap. That strap meaning goes back centuries. Australian English kept using thong for the simple sandal with a toe strap, while other places mostly shifted to flip-flops, so the Aussie meaning stuck and became everyday default.
Other ways to say it
This expression also appears in