metamour

[ met-uh-moor ]

noun

1. (among polyamorous people) a romantic or sexual partner of one's own romantic or sexual partner:

   I'm not dating her, but she's my boyfriend's girlfriend, so we are metamours.

Word History and Origins

Origin of metamour¹

First recorded in 1995–2000; meta- ( def ) + (par)amour ( def )

Example Sentences

A "metamour" refers to your partner's partner, and "compersion" refers to a sense of happiness you feel for a partner who is happy with another partner.

From Salon

Some people define “metamour” as a partner of our partners, whom we have a non-sexual and non-romantic relationship with.

From Slate