A correspondent identified only as J Hooker wrote a disgusted letter to the Lady’s Newspaper of London in January 1863 about slovenly and unhygienic rural servants in France:
If I were to do more than hint at their hydrophobic habits, their pulicidal, pulicivorous, and even phtheirophagous propensities, I should call down, not undeservedly, the Zoilism of our correspondents.
The writer — from the tone of the piece he is likely to have been the famous biologist Joseph Dalton Hooker — must have had an uncommonly large vocabulary, or a talent for word coining, for that set of alliterative insults is uncommon. The first two — pulicidal and pulicivorous — have not reached the pages of the Oxford English Dictionary, though their form suggests “flea-killing” and “flea-eating”, from Latin pulex. The third word, phtheirophagous, is from Latin, based on a Greek word that literally means louse-eating but was used figuratively for persons with unsavoury habits. The original epithet was applied by the Roman writer Strabo to a tribe living near the Black Sea, the Sulae, whom he disgustedly renamed the Phthirophagi.
Zoilism is another unfamiliar term. This is Greek and its initial capital letter gives the clue that it’s an eponym, a noun derived from a personal name. Zoilus was a Greek grammarian of the 4th century BC, who wrote savage criticisms of such Greek literary worthies as Homer, Plato and Socrates. He gained the nickname Homeromastic, one who assaults or chastises Homer.
Writers with good Greek but poor knowledge of word histories assumed that Zoilus and Zoilism were from the Greek word for zeal. This usually means an enthusiastic devotion to something (originally religion) but at one time could also imply jealousy or envy. This false connection caused people to assume that critics described as Zoilist were panning the work of others through resentfulness or spite.
There having never been any shortage of critics, Zoilus gained the plural Zoili. It and the other terms are now almost unknown, though bitter and carping criticism by envious hacks has not yet vanished from the world.