a student (usually university or college) who drops out at Christmastime when they go back home to visit their parents. Often caused by homesickness, academic failure, unpopularity, or a significant other living back at home.
Person 1: Man, did you hear that George isn't coming back after Christmas?
Person 2: Damn Christmas graduates.
Person 1: I need to move out of residence asap. Know of any places available?
Person 2: Wait until January when all the Christmas graduates sublet their apartments.