from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. To keep (a college or school athlete) out of varsity competition for one year in order to extend the athlete's period of eligibility.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. 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
- v. 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.
- v. To hold a child out of kindergarten for one year in the hope that the child will do better academically and socially.
- n. An unimportant character introduced only to be killed in order to underscore the peril to the important characters; an expendable character.
- n. A person responsible for loading and unloading weapons, artillery, and equipment from aircraft.
From the red jerseys worn by such athletes to distinguish them from the regular players.(American Heritage® Dictionary of the English Language, Fourth Edition)
red + shirt. From the red shirts worn by such people when on duty (Wiktionary)