Someone who is extremely obsessive about the videogame super smash brothers. this person has clearly spent his entire childhood and the majority of his/her teen years sitting in the darkness of their parents basement honing their smash skills until the wee hours of the morning while feasting on cool ranch doritos and cases of mountain dew. Smashfags make Super Smash Brothers completely unbearable and unfun. Whoever is playing against one will lose in less than 30 seconds and never play a smashfag ever again.
No, I don't want to play you in smash bros you fucking smashfag.