Slug-a-beds or slow-waking readers may not appreciate the virtues of this rare word, and will particularly dislike one of the compounds formed from it, ante-jentacular. That’s because it’s an adjective that refers to breakfast, especially one taken early in the morning or immediately after getting up.
It was created near the beginning of the eighteenth century, presumably by a Latin scholar who knew jentāculum, the Latin word for breakfast, and who felt a need for an adjective missing from the language. It had a fleeting period of rather ponderous popularity in the nineteenth century.
To valetudinarians and others the following method of making coffee for breakfast is earnestly recommended, as a most wholesome and pleasant jentacular beverage.
The New Family Receipt-Book, by John Murray, 1820.
Several of its appearances are linked to the philosopher and jurist Jeremy Bentham, best known for creating utilitarianism.
Bentham composed after playing a prelude on the organ, or while taking his “ante-jentacular” and “post-prandial” walks in his garden.
Harper’s New Monthly Magazine, Jul. 1852.
The general view of the world at large seems to be that breakfast needs no adjective, though breakfasty has been recorded a few times. You may feel that that’s an ungainly construction, no substitute for the elegant Latinate word. But jentacular is now as near defunct as a word can be in an era when most of English literature is searchable at the press of a button.