verb (used without object)
-(of a man) to make love with a woman one cannot or will not marry; carry on flirtations.
-To carry on a sexual affair, especially an extramarital affair, with a woman one cannot or does not intend to marry. Used of a man.
-To engage in many love affairs, especially with a frivolous or casual attitude. Used of a man.
1675–85; < Gk phílandros one who loves (of a woman, loving her husband); see philo-, andro-; later used in fiction as a proper name for a lover, and appar. mistaken as “a man who loves”
While this may have been an exaggeration on her part, my sister currently living in France once told me that she believed she knew no French man who did not philander.
My apologies to any French people here; this is just a sentence with no factual basis.