WordReference Random House Unabridged Dictionary of American English © 2025
u•ni•cos•tate
(yo̅o̅′ni kos′tāt, -kô′stāt),USA pronunciation adj.
- having only one costa, rib, or ridge.
- Botany(of a leaf ) having only one primary or prominent rib, the midrib.
- uni- + costate 1840–50