. | 1. | a rib or riblike part. |
| 2. | the midrib of a leaf in mosses. |
| 3. | a ridge. |
| 4. | Entomology.
|
costa cos·ta (kŏs'tə)
n. pl. cos·tae (-tē)
Rib.
A rodlike internal supporting organelle that runs along the base of the undulating membrane of certain flagellate parasites. Also called basal rod.