The Collaborative International Dictionary
Manswear
Manswear \Man"swear`\, v. i. To swear falsely. Same as Mainswear.
Wiktionary
manswear
vb. (context transitive UK dialectal English) To swear falsely; perjure oneself.
Usage examples of "manswear".
If by falling at his feet and owning herself to be vile and mansworn she might get his pardon, she was ready now to lie there on the ground before him.
Prestongrange promised me my life: if he's to be mansworn, here I'll have to die.