REDSHIRT
Etymology 1
Noun
redshirt (plural redshirts)
(US, collegiate sports) 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
Verb
redshirt (third-person singular simple present redshirts, present participle redshirting, simple past and past participle redshirted)
(US, collegiate sports) 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.
(US, collegiate sports) To take on a status wherein one will spend a year not participating in official athletic activities.
(US) To hold a child out of kindergarten for one year in the hope that the child will do better academically and socially.
Etymology 2
Noun
redshirt (plural redshirts)
(fiction, science fiction) An unimportant character introduced only to be killed in order to underscore the peril to the important characters; an expendable character.
Etymology 3
Noun
redshirt (plural redshirts)
(US navy) A person responsible for loading and unloading weapons, artillery, and equipment from aircraft.
Noun
Redshirt (plural Redshirts)
Alternative form of Red Shirt
Source: Wiktionary