manswear
To swear falsely; perjure oneself.
transitive
I require of thee, as a man of thy word, on pain of being held faithless, man-sworn, and nidering [footnote: Infamous], to forgive and to receive to thy paternal affection the good knight, Wilfrid of Ivanhoe.
Where it comes from
From Middle English mansweren, from Old English mānswerian (“to forswear, perjure oneself”), from mān (“bad, criminal, false”) + swerian (“to swear”).
Adapted from the Wiktionary entry manswear (CC BY-SA 4.0).