philanderer [M19th] Philanderer is a late development of earlier philander [L17th], a mainly poetic term for a male sweetheart and later a philanderer. This came from the ancient Greek adjective philandros ‘loving or fond of men’ and later of a woman ‘loving her husband’, formed from philo- ‘loving’ and -andros ‘man, male, husband’. Philander came to be used as a proper name in literature, especially for a lover, perhaps from a misunderstanding of the meaning as ‘a loving man’. By the late 18th century philander had come to be used as a verb for the actions of a man who indulged in casual sexual or romantic encounters, and from there it was a short step to form philanderer.