single-shoulder bikini
A bikini with an asymmetrical, diagonal-shaped neckline, leaving a portion of the upper chest area and at least one shoulder bare. These bikinis are typically supported by a single sleeve or a single strap on one shoulder while the other is left bare. The neckline of the bikini starts on top of one shoulder and ends underneath the armpit between the torso and opposite arm.
Examples include post #6542221, post #3736121, post #5350222, post #4230737, post #2936932, post #3659232, etc.
Do not confuse this tag for off-shoulder bikinis that expose one bare shoulder, or a regular bikini with its strap(s) slipping off from the shoulders.
Visual chart demonstrating what outfits qualify as a "single-shoulder shirt/dress/sweater/bikini/etc."
See also
This tag implicates bikini (learn more).