IPA: /ˈrɪb.ləs/
KK: /ˈrɪbləs/
Describing something that does not have ribs or rib-like structures.
The ribless design of the chair made it lightweight and easy to move.
Ribless → It is formed from "rib" (from Old English "ribbe", meaning a bone of the body) and "-less" (meaning without). The word "ribless" means without ribs or lacking ribs.
Think of being 'without' ('-less') 'ribs' — that's why ribless means lacking ribs.