There's a double usage to biff. Mainly in Northern Scotland.
Biff means "to go" or "has gone".
Biff also means, in polite terms, "go away and leave me alone", similar to "Fuck off".
1a. "Gonna biff up the shop in a few and get a 4 pack"
1b.
"Where's John?"
"He biffed over to his Mum's earlier to get his washing done"
2. "Biff off, prick... I don't wanna deal with your shit"
You biffed it! Why would u even try hitting that huge jump!
Best
Incredible
Fucking
Friend
she's my biff bitch back off
I know we've never met in real life but you're my biff. just sayin'. #NoHomo
Best Infinite Fucking Friend, when you find one you support each other until the universe stops.
"Put your hair up biffle before you fight!"