A person who has way too much time on their hands or obsesses over a certain thing. It can also be spelled as Feen or Fein.
Damian: "Yo, My brother was playing fortnite for 12 hours straight."
Eric: "Yeah, He's a fucking feind!"
Eric: "Yeah, He's a fucking feind!"
by KING Spitta May 01, 2018
by KING Spitta November 28, 2017