Definition of "begad"

You have a good name, good wits, good manners, and a good person—and, begad! I don't see why you shouldn't marry a woman with money—get into—distinguish yourself, and—and, in fact, that sort of thing.

1848 November – 1850 December, William Makepeace Thackeray, The History of Pendennis. […], volume I, London: Bradbury and Evans, […], published 1849, page 287

Begad, Perry, old fellow, all's well at last, eh?" exclaimed Anthony, grasping my hand. "What I mean to say is — will ye look at 'em, begad!.

1922, Jeffery Farnol, Peregrine's Progress‎, page 439