IPA: /ˈbæk.ləs/
KK: /ˈbæk.ləs/
Describing something that does not have a back, like certain types of chairs or dresses that are open at the back.
She wore a beautiful backless dress to the party.
Backless → It is formed from "back" (from Old English "bæce", meaning the rear part of the body) and "-less" (meaning without). The word "backless" describes something that lacks a back, such as a chair or a dress.
Think of something that is 'without' ('-less') a 'back' — that's why backless means it has no back.