when two people like each other but aren't going out, and know they both like each other, then one of them decides they don't want to go out with the other, and makes this known
Pete: ahh man! you know that girl? she's just pre-dumped me, shame, i thought we could've had something special
1. The act of being rejected before being given a chance, in which one party rejects the other before either has sufficient evidence to make any valid assessments of the other's character for fear of being legitimitely attracted to said rejectee. Most common when the rejecter is about to move away.
2. Preemptive rejection
"Jane just recently met someone; however, he is about to graduate from the university and though they got along great, she was predumped a few days ago."