Back in 1938, Paul Harvey wrote in The Oxford Companion to English Literature that “Titivil was evidently in origin a creation of monastic wit.”
He was thinking of the earliest sense of the word. A titivil was a very specific kind of tale-bearer. He was a devil whose job was to collect up the fragments of words or phrases that monks skipped or mumbled while they were reciting divine service. He took them down to Hell, where they were logged against the offender to await the Day of Judgement. Might he have been invented as a way to scare the less conscientious members of monastic congregations into saying their prayers properly? It seems more than likely.
He wasn’t English to start with. He turns up in continental Europe in the fourteenth century under various names, including Titinillus and Titivillus. He’s mentioned in a sermon dated to the early 1300s by a Dominican monk named Petrus de Palude who later became Patriarch of Jerusalem: “Fragmina psalmorum Titiuillus colligit horum. Quaque die mille vicibus sarcinat ille” (Titivillus collects up fragments of these psalms. Every day he fills his bag a thousand times.) One guess is that his name was from the Latin word titivillitium used by the Roman comic dramatist Titus Maccius Plautus and which seems to have meant a mere trifle or a trivial bit of gossip.
Around the same period, Titivil became a convenient scapegoat in monastery scriptoria. The inevitable little accidents that happen when copying manuscripts, such as jogging of elbows and skipping of pens that caused blots, false strokes, and ink smears, were also attributed to him.
Titivil escaped from the cloisters into the medieval mystery plays and from there into the colloquial language as a mischievous tale-bearer or more generally a ne’er-do-well or scoundrel. He vanished from common usage around the beginning of the seventeenth century and this is among his last appearances:
Coquette: A pratling, or proud gossip; a fisking or fliperous minx; a cocket, or a tatling housewife; a titifill, a flebergebit.
A Dictionarie of the French and English Tongues, by Randle Cotgrave, 1611. The definition is worse than the original word for modern readers because so many of the terms are unfamiliar: pratling is from prattle and meant gossiping; fisking meant flighty or frisky; the OED does not define fliperous and it appears nowhere else but here; cocket is just an early English spelling of coquette; tatling meant passing on tittle-tattle; flebergebit would now be spelled flibbertigibbet. And proud then meant haughty or arrogant.