the.com/ignoramus
A confidently wrong person, blissfully unaware they skipped every memo.
means An ignorant or stupid person, especially one who acts certain despite knowing nothing.
from Latin for we do not know, once stamped on legal documents by grand juries to dismiss flimsy cases; a 1615 stage farce starring a clueless lawyer named Ignoramus dragged it into the insult business.
Plural debateIgnoramuses, not ignorami, since it was a verb.
Legal verdictJuries wrote it to reject weak indictments.
Stage originA 1615 comedy made it an insult.