Paramour

Webster's Dictionary of the English Language

·noun Love; gallantry.

II. Paramour ·adv ·Alt. of Paramours.

III. Paramour ·noun A lover, of either sex; a wooer or a mistress (formerly in a good sense, now only in a bad one); one who takes the place, without possessing the rights, of a husband or wife;

— used of a man or a woman.