Editorial Note: A similar—but not identical—term is redshirt. The differences depend on the sport and the league, but this article (scroll about halfway down the page) and this one offer more detail.
Citations:
[1992 Jorge Valencia, Maureen Delany Press-Enterprise (Riverside, California) (Oct. 1) “Poly star plays bigger than he looks” p. C8: But he injured his left knee and took a grayshirt year (going to school part time without losing a year of eligibility).] 1993 Carl Sawyer Orange County Register (California) (Dec. 4) “Bowl games a feast for scouts” p. C12: Even before deciding on Orange Coast, I knew I was going to grayshirt. I have dyslexia (a reading-learning disability), and I felt that I needed to take some classes and learn what college is all about before I tried playing ball. 2005 Gentry Estes Ledger-Enquirer (Columbus, Ga.) (Jan. 9) “Tide builds to 85 scholarships”: Three players off the Crimson Tide’s 2004 signing class were forced to grayshirt this season, meaning they could enroll in school, but there simply wasn’t enough room to officially add them to the team until 2005.