I. ˈträth, ˈtrȯth, ˈtrōth, or with th noun
Etymology: Middle English trouth, from Old English trēowth — more at truth
Date: 12th century
1. : loyal or pledged faithfulness : fidelity
pledged my troth
2. : one's pledged word
I don't remember the details or, by my troth , even the gist — Stanley Elkin
also : betrothal
II. transitive verb
Date: 14th century
: pledge , betroth