A "strapless neckline" refers to a type of neckline on a piece of clothing, such as a dress or top, that has no straps or sleeves covering the shoulders. Full definition
Front fitted bodice is encrusted with strapless neckline fixed by a satin belt at front natural waist which leads down a white satin and organza skirt that completes with chapel train back. (wepromdresses.net)
This chiffon dress features strapless neckline and pink sashes. (weddingdresstrend.com)
Sexy strapless neckline with ruched trim and fitted natural waistline falls into knee length skirt finishes the sexy look. (wepromdresses.net)