A strapless bra is a type of bra that does not have any straps around the shoulders. It is designed to be worn with outfits that have a bare or off-shoulder neckline. Full definition
Was able to wear strapless bra with dress and tug down a bit which was SO awesome to not have to buy something special! (renttherunway.com)
Be aware that feeling uncomfortable with strapless bra on, you must have picked the wrong size. (rosegal.com)
UNDERGARMENTS: Should be worn with a racerback or strapless bra FABRIC Fabric has no stretch GREAT FOR: Apple, Athletic, Bump Friendly, Hourglass, Pear, Petite, Tall, Straight & Narrow body types (Model's height is 5» 10».) (renttherunway.com)