single-shoulder dress
A dress with an asymmetrical, diagonal-shaped neckline, leaving a portion of the upper chest area and at least one shoulder bare. These dresses are typically supported by a single sleeve or a single strap on one shoulder while the other is left bare. The neckline of the dress starts on top of one shoulder ends underneath the armpit between the torso and opposite arm.
Examples include post #4485930, post #3689434, etc. The female variation of the Dancer outfit from Fire Emblem: Three Houses is also a good example of this tag.
Do not confuse this tag for off-shoulder dresses that expose one bare shoulder.