also costar, 1915 as a noun; 1916 as a verb; from co- + star (v.).
Entries linking to co-star
co-
in Latin, the form of com- "together, with" in compounds with stems beginning in vowels, h-, and gn-; see com-. Taken in English from 17c. as a living prefix meaning "together, mutually, in common," and used promiscuously with native words (co-worker) and Latin-derived words not beginning with vowels (codependent), including some already having it (co-conspirator).
star v.
1590s, "to affix a star or asterisk to," from star (n.). From 1718 as "to set with stars." Meaning "perform the lead part" (of actors, singers, etc.) is from 1824. Sporting sense is from 1916. Related: Starred; starring.