1. To be classic-modern
2. To have classic charm and modern sensibilities
3. The process by which someone gets their ass beat in high school.
4. A racial slur in lower Ireland
Ex. The Black Keys are fucking Classmo. Sounds like some bitching ass motown produced in 0'ten.
Ex. "I'm sick of these fucking classmo's coming into our homes with their jungle music." - Drunk O'Donnashirehoof