athlete’s clock
n.— «The Huskies had hoped Miller would still be granted four years of eligibility and that the five-year window each athlete is given—commonly called an athlete’s clock—would not have started in that summer of 2006.» —“Miller settles in at tackle for UConn” by Neill Ostrout in Storrs Connecticut Post (Bridgeport) Mar. 31, 2008. (source: Double-Tongued Dictionary)