Definitions by Just some random guy.

OP 

O.p. means overpowered which most gamers use while playing video games.

Bro that guy has a fully auto magic gun with a scope and rocket laucher. That's op!!

OP by Just some random guy. January 2, 2017

Foot size 

Foot size is a low key meaning for penis length. Commonly only adults know this.

Girl: I just love him so much.
Guy: Oh yeah well what's his foot size??
Girl: Foot size doesn't matter.

Foot size by Just some random guy. December 25, 2016

Foot size 

Refering to a man's penis size (length)

He's a nerd I bet his foot size is tiny!

Foot size by Just some random guy. December 25, 2016