A boyfriend, a male significant other, the guy you're dating. The term was first coined in Seattle.

boyfriend = bf
bf = bee ef
bee ef = beef

To fail to complete a surfing/skateboarding/snowboarding/biking, stunt, by crashing usually involving bodily harm.

This is when someone really messes up while doing somthing simple.

When you have lights off sex with someone without telling them you’re on your period

The male version of a queef. When the fart rolls underneath your balls and escapes out the front.

Verb (not conjugable). Teens. From italian slang "Stai manzo".
Also written "Stay beef". (Litteraly italian to english translation).
Used by Italian who don't know well English. It means "relax".

At cut of meat from a cow