costar

Etymology

From co- + star.

noun

1. (acting) a person who shares star billing
   The once famous actor objected to his costar having a bigger dressing room.
2. (acting) a person who slightly lacks the status to be considered a star
   Alas, always a costar but never a star.

verb

1. to perform with the billing of a costar.
   People thought his career was over but now he will get to costar on Broadway next month.
   Purchasing a snowplow transforms Homer into a new man. Mr. Burns' laziest employee suddenly becomes an ambitious self-starter who buys ad time on local television at 3:17 A.M (prime viewing hours, Homer gingerly volunteers, for everyone from alcoholics to the unemployable to garden-variety angry loners) and makes a homemade commercial costarring his family. June 3, 2012, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “Mr. Plow” (season 4, episode 9; originally aired 11/19/1992)”, in (Please provide the book title or journal name)