co·​star | \ ˈkō-ˌstär How to pronounce costar (audio) \
variants: or co-star
plural costars or co-stars

Definition of costar

 (Entry 1 of 2)

: one of two or more main performers who star in a motion picture, play, etc. … the star seems more relaxed and confident, and there's a bracing snap to the byplay between him and his costars.— Mark Harris


variants: or co-star
costarred or co-starred; costarring or co-starring

Definition of costar (Entry 2 of 2)

1 transitive : to employ or present (someone) as one of two or more leading performers in a motion picture, play, etc. Directed by Lasse Hallström … and costarring a fine ensemble …— Leonora Langley
2 intransitive : to appear with another star in a motion picture, play, etc.

Examples of costar in a Sentence

Recent Examples on the Web: Noun

People were quick to speculate and Porowski’s comment section was bombarded with comments asking if the kiss indicated the start of a relationship between the costars. Claudia Harmata,, "Queer Eye's Antoni Porowski and Jonathan Van Ness Stir Relationship Rumors With Kissing Photo," 5 July 2019 Get a picture of that: Allison Janney and Ellen Barkin are the most smartest costars in the world. Joey Nolfi,, "Allison Janney, Ellen Barkin hold most smartest Drop Dead Gorgeous reunion," 28 June 2019 The couple and several costars flew out this week to start preparations at the castle. Emma Austin, The Courier-Journal, "'Vanderpump Rules' costars are getting married at the Kentucky Castle," 28 June 2019 The duo is joined by Andrea Carpenzano, the costar of Boys Cry. Vogue, "25 Ways to Gucci: Rome’s Creative Class," 29 Nov. 2018 Her costar, Emilia Clarke shared similar sentiments. Lauren Rearick, Teen Vogue, "Game of Thrones Stars Emilia Clarke and Sophie Turner Shared Heartfelt Tributes to the Show in Honor of the Finale," 20 May 2019 Emma Thompson, Rebecca Ferguson and Kumail Nanjiani and various aliens costar. Randy Myers, The Mercury News, "Weekend movies: ‘Men in Black,’ ‘Shaft’ are back," 11 June 2019 The other is her X-Men: Dark Phoenix costar, Tye Sheridan. Marie Claire, "Sophie Turner Says She's "In Love" With Her 'X-Men' Costar Tye Sheridan and Joe Jonas Is Totally Okay With It," 30 Mar. 2019 And that included Sally Field, Reynolds’ former costar — and girlfriend. Megan Friedman, Good Housekeeping, "Sally Field Remembers Burt Reynolds in Emotional Statement About Their Relationship," 7 Sep. 2018

Recent Examples on the Web: Verb

The film costars Greg Bryk, Stephen McHattie, and Ted Atherton. Clark Collis,, "Rabid remake gets disturbing first trailer," 4 July 2019 Williams’ Girls costars Lena Dunham, Jemima Kirke, and Zosia Mamet were among the guests in attendance, as well as Katy Perry, Seth Meyers and John Mayer. Alexis Reliford,, "After Nearly 4 Years Together, Allison Williams & Husband Split," 30 June 2019 The international production is in English, German and French and costars Lizzy Caplan and Vincent Kartheiser. Sean Axmaker | Stream,, "Home viewing this week: ‘Us,’ ‘City on a Hill,’ ‘Das Boot’ (2018), ‘Hotel Mumbai,’ ‘Beats’," 21 June 2019 Lead by Thor: Ragnarok costars Chris Hemsworth and Tessa Thompson, the film made just $28.5 million domestically this past weekend. Angela Watercutter, WIRED, "Men in Black: International," 17 June 2019 The actress’ Girls Trip costar Tiffany Haddish will present the award. Tyler Aquilina,, "Jada Pinkett Smith will receive 2019's Trailblazer Award at the MTV Movie & TV Awards," 11 June 2019 Thankfully, he and costar Kathryn Newton had actual sets built and filmed on location in London and Scotland to anchor the astonishing world of Pokémon. Gabe Bergado, Teen Vogue, ""Pokémon Detective Pikachu" Star Justice Smith on the Power of Representation, Fans Dressing Up as Tim Goodman, and Sequel Ideas," 17 May 2019 Guests include her former Suits costar Abigail Spencer and designer Misha Nonoo. Erica Gonzales, Harper's BAZAAR, "Who's Attending Meghan Markle's Baby Shower in NYC?," 19 Feb. 2019 After her triumphant stand-up specials (2016’s Baby Cobra and 2018’s Hard Knock Wife), Wong has penned the film with Randall Park, who will also costar. Vogue, "Watch a Trailer for the New Netflix Ali Wong Rom-Com, Always Be My Maybe," 23 Apr. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'costar.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of costar


1888, in the meaning defined above


1896, in the meaning defined above

Keep scrolling for more

Learn More about costar

Statistics for costar

Last Updated

13 Jul 2019

Look-up Popularity

Time Traveler for costar

The first known use of costar was in 1888

See more words from the same year

Keep scrolling for more

More Definitions for costar



English Language Learners Definition of costar

: one of two or more main actors in a movie, television show, or play

More from Merriam-Webster on costar

Rhyming Dictionary: Words that rhyme with costar

Spanish Central: Translation of costar

Comments on costar

What made you want to look up costar? Please tell us where you read or heard it (including the quote, if possible).


something desired as essential

Get Word of the Day daily email!

Test Your Vocabulary

What's that Smell?! Quiz

  • wide eyed dog smelling rose
  • Someone who is hircine smells like a:
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!