Definition of costate in English:
 costate
adjective ˈkɒsteɪtˈkäsˌtāt
Zoology Botany Ribbed; possessing a costa.
 Example sentencesExamples
-  Early genera were almost circular to elongate-oval, with smooth or finely costate shells.
 -  Lateral slopes are weakly costate; the costae are diminished and almost invisible.
 -  The only other Eurasian finely and densely costate species known to me that is closely comparable is Leptochondria minima from the Lower Triassic of Russia.
 -  In pioneer studies, the genus was confused with some spire-bearing brachiopods because of its strophic outline and costate ribbing.
 -  All are radially costate, with costae varying from simple and evenly distributed to variously branched and unevenly spaced.
 
Origin
  
Early 19th century: from Latin costatus, from costa 'rib'.