One of the dozens of slang terms used by Beavis and Butt-head. Buttknocker could refer to
a)A homosexual, as anal sex is the only form of intercourse for gay men, or
b)An erection in somebody's ass, referring to pulling out and then tapping and wiping the semen on said ass.
Beavis: Shut up, Butt-head! I'm gonna play drums on your nads with my foot!
Butt-head: I'd like to see you try, buttknocker!
Beavis: Don't call me that, Butt-head! (Beavis kicks Butt-head in the testicles)
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.
We have a Zoom meeting in a few minutes and I’ll probably go pajama casual.