A person who is stupid and doesn't have basic knowledge.
Person 1: I don't need to know about real world problems.
Person 2: You're a rat.
A beautiful rat is a friend who's a rat just like me. My cousin is a fine example.
Someone in a game who uses annoying stratagies to win. Sometimes also refered to as mole rat
P1: *Kills P2 in Call Of Duty with a riot shield*
P2: Oh my god kill yourself you rat!
A person who says they will get you something but doesn't and gets someone else it instead
For example Osama bin Poomin was a rat for buying ChinJake an ambernick instead of his own sister
Someone who is manipulative and unable to differentiate between political operation and their personal life.