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 co-star

Contemporary Examples of co-star

She said that her co-star, Alfre Woodard, talked to her about it a cocktail party that night.
It’s Time to Stop Hating Katherine Heigl
Kevin Fallon
November 17, 2014
He talks about the first sexual encounters he had with a man, a co-star from when he was starring in Rent on Broadway.
Choose Your Own Neil Patrick Harris: The Star on ‘Doogie,’ ‘Gone Girl,’ Gay Sex and More
Kevin Fallon
October 10, 2014
Both Sheldon Leonard, who created the show, and Robert Culp, who was his co-star, were socially conscious.
A Full-Length Bill Cosby Portrait: From Track Star to Ugly Sweaters
Scott Porch
September 24, 2014
The story of how it was orchestrated—by co-star Julianna Margulies, no less—has been endearingly documented.
Josh Charles on Life After ‘The Good Wife’ and His Insane Movie ‘Bird People’
Kevin Fallon
September 13, 2014
So, Streep rewrote much of her dialogue, which led to tension with her co-star, Hoffman, who felt she was trying to upstage him.
Co-Stars Who Hated Each Other: Ryan Gosling and Rachel McAdams in 'The Notebook' and More
Marlow Stern
July 4, 2014

British Dictionary definitions for co-star

co-star

noun

an actor who shares star billing with another

verb -stars, -starring or -starred

(intr often foll by with) to share star billing (with another actor)
(tr) to present as sharing top billingthe film co-starred Mae West and W. C. Fields

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for co-star

also costar, 1919 as a verb; 1926 as a noun, from co- + star (v.).