1. slang An intensely painful headache or migraine. It started as just a twinge of pain in my forehead, but by the end of the day I was in the throes a full-blown skull-buster. It was a great night, but I woke up with a real skull-buster and the worst nausea of my life.
2. slang Something very confusing, complicated, or puzzling. A: "There just doesn't seem to be a way we can reach our quotas without going over budget." B: "It's a skull-buster, to be sure." I love trying to figure out the crosswords in the newspaper each Sunday. Today's is a total skull-buster!
1. n. a difficult course in school or college. The course was a skull-buster, and I had to drop it.
2. n. a police officer. (Refers to the striking of skulls.) Two skull-poppers came up and started asking questions.