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

Even her Idol costars took the opportunity to teases her a little bit. Glamour, "Katy Perry Had a Complete Meltdown During This American Idol Proposal," 27 Mar. 2019 Zac was suspected to be dating his Baywatch costar Alexandra Daddario back in 2017. Carolyn Twersky, Seventeen, "Everything You Need to Know About Zac Efron's Love Life," 6 Mar. 2019 Although their performance was epic, Cooper was nervous to take the stage with his multi-time Grammy winner costar. Erica Gonzales, Harper's BAZAAR, "Lady Gaga and Bradley Cooper Gave the Most Intimate Performance the Oscars Has Ever Seen," 25 Feb. 2019 Following the controversial news released earlier this month that Claire Foy was paid significantly less than her male costar Matt Smith on The Crown, the actress—who played Queen Elizabeth II on the hit show for two seasons—has finally spoken out. Christian Allaire, Vogue, "Claire Foy Isn’t Surprised by The Crown’s Pay-Gap Controversy," 25 Mar. 2018 Their most recent collaboration is Nanny McPhee Returns, opening this month, which Emma — who won an Oscar for her screenplay for Sense and Sensibility — wrote, produced, and costars in. Jenny Allen, Good Housekeeping, "Between Friends," 7 July 2010 When a celebrity starts dating a costar, people go nuts. Kayleigh Roberts, Marie Claire, "Lili Reinhart and Cole Sprouse Just Trolled Their Own Relationship on Instagram," 14 Oct. 2018 Since the original Roseanne program ended in 1997 after nine seasons, Galecki has continued to keep in touch with a few costars. Karen Mizoguchi,, "Johnny Galecki Felt ‘Very Emotional’ About Returning to Roseanne: 'It Was Much More Personal'," 15 May 2018 The power ballad, which Gaga sings with costar Bradley Cooper in the musical film, has won the award for Best Song Written For Visual Media, the Recording Academy announced this afternoon. Erica Gonzales, Harper's BAZAAR, "Lady Gaga Wins Grammy for "Shallow" Before the Ceremony Starts," 10 Feb. 2019

Recent Examples on the Web: Verb

Expected guests include designer Misha Nonoo, her former Suits costar Abigail Spencer, Serena Williams (who reportedly helped organize), and more. Amy Mackelden, Harper's BAZAAR, "Meghan Markle Is Hosting Her Real Baby Shower Today in NYC," 20 Feb. 2019 Just because Brown won’t be there doesn’t mean her Stranger Things costars won’t be. Dave Quinn,, "Millie Bobby Brown Splits Kneecap, Forcing Her to Skip the MTV Movie & TV Awards: 'Another Milestone'," 16 June 2018 Borstein also thanked her team and costars at Mrs. Maisel—the Amazon hit starring Rachel Brosnahan as the titular stand-up comedian—and her family. Erica Gonzales, Harper's BAZAAR, "Alex Borstein Accepted Her Emmy Award Without a Bra and We're All Inspired," 18 Sep. 2018 Along with Capshaw, costars Justin Chambers and Caterina Scorsone are featured in the hilarious gag reel. Karen Mizoguchi,, "Jessica Capshaw Shares Grey’s Anatomy Bloopers Featuring Ellen Pompeo Before Final Episode," 16 May 2018 On April 5, Lynch shared a picture of himself and costar Shipka in character as Harvey and Sabrina on Instagram. Kayleigh Roberts, Marie Claire, "Everything You Need to Know About the New 'Sabrina the Teenage Witch' TV Show," 1 Aug. 2018 Natasha Lyonne costars in Orange Is the New Black, which returns to Netflix this month. Samantha Leach, Glamour, "Read Natasha Lyonne's Love Letter to Her 'Odd Couple' Other Half, Rosie O'Donnell," 26 July 2018 Perhaps the most telling sequence involves Arnold staking out the favorite restaurant of his old True Lies costar, Arnold Schwarzenegger, in the second episode. Todd Vanderwerff, Vox, "The Hunt for the Trump Tapes with Tom Arnold, explained," 18 Sep. 2018 During an Wednesday, August 8 appearance in support of her upcoming film Slender Man, Joey King received a show of support from former Kissing Booth costars Jacob Elordi and Joel Courtney. Lauren Rearick, Teen Vogue, ""The Kissing Booth" Cast Reunited at the Premiere of Joey King's New Movie "Slenderman"," 9 Aug. 2018

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

20 Apr 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).


to move or proceed with twists and turns

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Latin Quiz

  • roman forum
  • Which of the following months comes from a Latin word for “ten”?
Spell It

Can you spell these 10 commonly misspelled words?

Bee Cubed

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!