Etymology
From Middle English hath, heth, hafth, hefth, from Old English hæfþ, hafaþ (“has”), from Proto-Germanic *habaiþi (“has”), equivalent to have + -th. Cognate with Saterland Frisian häd (“has”), West Frisian hat (“has”), Dutch heeft (“has”), Afrikaans het (“has, have”), German Low German hett (“has”), German hat (“has”).
Verb
hath
- (archaic) third-person singular simple present indicative of have
Thirty days hath September.
1611, Joseph Hall, “Epistle VIII. To E.B. Dedicated to Sir George Goring.”, in Epistles […], volume III, London: […] [William Stansby and William Jaggard] for Samuell Macham, […], →OCLC, 5th decade, pages 95–96:To ſet the minde on the racke of long meditation (you ſay) is a torment: to follow the ſwift foote of your hound alday long, hath no wearineſſe: what would you ſay of him that finds better game in his ſtudie, then you in the fielde, and would account your diſport his puniſhment? ſuch there are, though you doubt and wonder.
1726 October 28, [Jonathan Swift], “A Further Account of Glubbdubdrib. […]”, in Travels into Several Remote Nations of the World. […] [Gulliver’s Travels], volume II, London: […] Benj[amin] Motte, […], →OCLC, part III (A Voyage to Laputa, Balnibarbi, Glubbdubdribb, Luggnagg, and Japan), page 108:I could plainly diſcover from whence one Family derives a long Chin; why a ſecond hath abounded with Knaves for two Generations, and Fools for two more; why a third happened to be crack-brained, and a fourth to be Sharpers.
1749, Henry Fielding, chapter I, in The History of Tom Jones, a Foundling, volume IV, London: A[ndrew] Millar, […], →OCLC:To be plain, I much question whether the politician, who hath generally a good nose, hath not scented out somewhat of the utility of this practice.