/ Dictionary / Index C costa: Meaning and Definition of Find definitions for: cos•ta Pronunciation: (kos'tu, kô'stu), [key] — pl. cos•tae a rib or riblike part. the midrib of a leaf in mosses. a ridge. Also calledcos&prim;tal vein&prim;.a vein, usually marginal, in the anterior portion of the wing of certain insects. Also calledcos&prim;tal mar&prim;gin.the anterior edge or border of the wing of certain insects. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: costa (Thesaurus) cost Costa Brava Related Content Daily Word Quiz: supine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language