E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Ignora’mus.
One who ignores the knowledge of something; one really unacquainted with it. It is an ancient law term. The grand jury used to write Ignoramus on the back of indictments “not found” or not to be sent into court. Hence ignore. The present custom is to write “No true bill.”
