backless
Word family
Synonym discussion
Sense: adjective/1
All four describe garments by what fabric is missing, but they pick out different parts of the body. 'Backless' means the back is mostly bare, with little or no fabric behind the wearer; it is the strongest of the group and is common in fashion writing for evening wear. 'Low-backed' is milder — the back is cut deep but still has some fabric, often down to the waistline. 'Open-backed' overlaps with backless but is more often used in catalogues for tops and swimsuits. 'Strapless' is unrelated to the back: it describes a top with no shoulder straps, so the shoulders are bare instead. A dress can be both strapless and backless (no shoulder straps and an open back), or just one of the two.
Common collocations
Etymology
Formed in English by adding the suffix '-less' (meaning 'without') to the noun 'back'. The pattern dates back to Old English, where '-leas' was used to make adjectives describing the absence of something (compare 'hopeless', 'endless'). 'Backless' itself appears in English from the 19th century, first describing furniture without a backrest and later, in the 20th century, becoming common in fashion writing for garments cut to leave the wearer's back exposed.