Etymology
The adverb is derived from Middle English par amour, paramore, paramours (“with sexual desire or love, passionately; in a courteous or friendly manner”), from Anglo-Norman par amur (“in a friendly or willing manner”) and Old French par amur, par amour, paramours (“by or through love”) (modern French par amour), from par (“by; through; etc.”) (from Latin per (“by means of, through”), ultimately from Proto-Indo-European *per- (“to go through; etc.”)) + amor, amur (“love”, noun) (from Latin amōrem, the accusative singular of amor (“desire, lust; affection, love”), from amō (“to love”) (possibly ultimately from Proto-Indo-European *h₃emh₃- (“to grasp, seize; to take hold; to touch; etc.”)) + -or (suffix forming abstract nouns)).
The noun is from Middle English paramour, paramoure, paramur, per