Kate Gladstone of Handwriting Repair emailed me about the possibility that the plural form "ignorami" is incorrect, and that one of her teachers would likely have beaten me with a yardstick had I attended the same school as Kate:
Dear Mr. Brooks —Kate is correct that "ignoramus" is the first person plural of the Latin verb ignorare ("to not know"). In my defense, I relied upon the Merriam-Webster Dictionary, which lists ignorami as an acceptable plural form of ignoramus.
The word "ignoramus," a Latin verb-form meaning "we do not know," has no Latin plural-noun form. Therefore, when used as an English noun it correctly pluralizes as "ignoramuses."
(Or, as I learned from a teacher who showed more erudition than tact: " 'Ignorami' is used by ignoramuses.")
Yet even Merriam-Webster has trouble reaching a consensus on the ignoramuses versus ignorami debate. In the 1994 Dictionary of English Usage, the editors at Merriam-Webster specifically argued against the much-maligned "ignorami." However, in the interest of throwing the weight of this mighty little blog on one side, I suggest that diligent writers resist the urge to use ignorami, except as a weapon to tweak the cheeks of grammar mavens, or if you want to puzzle the employees of a real estate franchise.