Third-person singular simple present indicative form of costar.(verb)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "costars" in a sentence
"I just saw Curtains, and its star, Debra Monk, (who had a recurring role as Andy Sipowiecz's first wife on NYPD Blue), has been on L&O, as well as 3 of her Curtain costars: Karen Ziembra, John Bolton, Michael McCormick."
"Now, basically, I think you can't go wrong with a Hugh Grant romcom, and if you can overlook Drew's frequent bad taste in costars, you pretty much can't go wrong with her, either."
"Then John C. Reilly delivered some scripted Vampire’s Assistant banter with his costars from the film and gave out the award for Female Break-out Performance, which went to the other Transformers hottie, Isabel Lucas."