- costa - a riblike part of a plant or animal (such as a middle rib of a leaf or a thickened vein of an insect wing)
--1 is a kind of structure, anatomical structure, complex body part, bodily structure, body structure
- rib, costa - any of the 12 pairs of curved arches of bone extending from the spine to or toward the sternum in humans (and similar bones in most vertebrates)
--2 is a kind of bone, os
--2 is a part of vertebrate, craniate
--2 has parts: costal cartilage
--2 has particulars: true rib - rib, costa - any of the 12 pairs of curved arches of bone extending from the spine to or toward the sternum in humans (and similar bones in most vertebrates)