ignoramo
A foolish and ignorant person; an ignoramus.
rare
'Did you see him when I asked him his opinion of the new champers?' Biddy tittered. 'He went red as fire! What an ignoramo!'
Where it comes from
Clipping of ignoramus + -o. Possibly modelled on Spanish and Italian verb forms ending in -o.
Adapted from the Wiktionary entry ignoramo (CC BY-SA 4.0).