redshirted, adj. — Green’s Dictionary of Slang

redshirted adj.

[college sports jargon redshirt, an athlete taking a year off from playing sport to extend their eligibility as a ‘student’]

(US campus) jilted.

1996

Eble Sl. and Sociability 13: Sometimes a new slang form either replaces an earlier one or provides another synonym for a notion already named in slang, like [...] red-shirted and latered for ‘jilted’.