Stan Twitter language meaning something has flopped in contrast to something else. "outflopped" has the opposite meaning of "outsold". Commonly used to talk about artists’ sales/careers but can be applied to other things.
Derived from: flop, outsold
Friend 1: Did you hear that new Ariana Grande song? It’s so good!
Friend 2: Nah, Ariana outflopped. Anyways, stream Azealia Banks.