costar

or co-star

[noun koh-stahr; verb koh-stahr]

noun

a performer, especially an actor or actress, who shares star billing with another.
a performer whose status is slightly below that of a star.

verb (used without object), co·starred, co·star·ring.

to share star billing with another performer.
to receive billing of slightly less status than that of a star.

verb (used with object), co·starred, co·star·ring.

to present (two or more actors) as having equal billing or prominence.
to present as having slightly less status than that of a star.

Origin of costar

An Americanism dating back to 1915–20; co- + star

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for costar

Contemporary Examples of costar

During the filming of To Die For, Affleck shared an apartment in Toronto with his costar, Joaquin Phoenix.
Casey Affleck, Star of ‘Out of the Furnace,’ on His Hollywood Struggles
Marlow Stern
December 2, 2013
Wait… and Shailene, the star of that, is your costar in The Spectacular Now.
Brie Larson On ‘Short Term 12,’ One of the Year’s Best Films
Marlow Stern
August 25, 2013
Usher Monteith's onscreen romance with costar Lea Michele wasn't hard to fake: the two actors were dating in real life as well.
Cory Monteith’s Best ‘Glee’ Performances
Jake Heller
July 14, 2013
The two produced, co-wrote, and costar in Promised Land, the new drama out Friday.
Matt Damon and John Krasinski Talk About Their Bromance, ‘Promised Land,’ and More
Kevin Fallon
December 26, 2012
There was costar Jim Sturgess coming up to hug her, and there was Susan Sarandon giving the director a kiss on the cheek.
The Wachowskis’ ‘Cloud Atlas’ Wows Toronto International Film Festival
Chris Lee
September 9, 2012

Historical Examples of costar

A little of Costar's well-known exterminator would rid Mr. Aldrich of this rascal rodent.
The Atlantic Monthly, Volume 18, No. 106, August, 1866
Various
Voiture and Costar frequently cite him as a model in their letters.
A Philosophical Dictionary, Volume 10 (of 10)
Franois-Marie Arouet (AKA Voltaire)