—n., v., -starred, -star•ring.
a performer, esp. an actor or actress, who shares star billing with another.
a performer whose status is slightly below that of a star.
to share star billing with another performer.
to receive billing of slightly less status than that of a star.
to present (two or more actors) as having equal billing or prominence.
to present as having slightly less status than that of a star. Also,co'-star".
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.