What is Ignoramous?
A really ignorant person. Someone who doesn't know how the world works, and doesn't CARE to know.
Boyo, you are such an ignoramous. Can't you learn to shut your mouth while you chew your food?
Officially: An offensive term that deliberately insults somebody's level of intelligence or education.
In slang: A person who is completely ignorant, an ass, a prik, idiot, etc.
That guy's ignoramous. I despise him.