A
one-piece bathing (or tanning) suit for women:
1. just a
bottom piece, hence a euphemism for topless
2. a bikini whose top and
bottom pieces are connected by cloth either a) on the front, b) the back or c) both, but with the kidney area uncovered
3. much like #2 but with a neckholder and no strings on the back
4. jokingly for a classic swimsuit which covers much of the torso or even for a burkini
This can lead to misunderstandings, obviously.