Depending on where you're from in the world, flip-flops are also known as thongs, pluggers, slaps, slippers, havaianas, and go-aheads. Just to name a few! The term “flip-flop”has been used by both Americans and Brits since about 1972 to describe a rubber-type thong sandal. It got its name from the sound it makes when its worn … flip … flop. A very poetic name … I think that's onomatopoeia.
When we visited the tiny island nation of Niue in the South Pacific, our friend Keith took us for an island tour. He mentioned the jandal cemetery as we passed by a beach. We weren't sure what we were looking for… tiny dead animals, maybe? No, it was a beach that seemed a magnet for errant flip-flops that had escaped from somewhere and washed ashore. Jandal, as the New Zealanders call them, is short for Japanese sandals and the beach was covered with them.
Some folks live in them in favor of other shoes or sandals. I personally don't like them for regular wear, but use them when I'm showering in “iffy” showers. The Aussies call them thongs and when we first arrived, we experienced some language issues when folks told us a party was informal, just wear shorts and thongs. Hmmm... for me thongs are dental-floss underwear with the floss in your butt crack. No matter how informal the party was, there was no way I was wearing a thong to it. Then, of course, I saw everyone in flip-flops. What a relief. I didn't have to wear a thong after all; nor did I have to watch anyone else wear one.