redshirt
noun
°an athlete who spends a year not participating in official athletic activities, but does not lose his or her eligibility to participate in following years.
°(fiction science fiction) An unimportant character introduced only to be killed in order to underscore the peril to the important characters; an expendable character.
verb
°to place an athlete in a status wherein the athlete will spend a year not participating in official athletic activities, but will not lose his or her eligibility to participate in following years.
°To hold a child out of kindergarten for one year in the hope that the child will do better academically and socially.