The year after graduating high school during which one sleeps for an entire year instead of going to college. After one wakes up, college begins. A sleepyear is used as a way to fully regain one's energy after the exhausting years of high school, so as to be fully awake and ready to get down to business in college.
Guy 1: "Ready for college next year?"

Guy 2: "Nah, next year's a sleepyear."
by Arock93 March 16, 2011
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