IGNORAMUS, n.

A person unacquainted with certain kinds of knowledge familiar to yourself, and having certain other kinds that you know nothing about.

Dumble was an ignoramus,
Mumble was for learning famous.
Mumble said one day to Dumble:
"Ignorance should be more humble.
Not a spark have you of knowledge
That was got in any college."
Dumble said to Mumble:  "Truly
You're self-satisfied unduly.
Of things in college I'm denied
A knowledge--you of all beside."

Borelli