The colloquial term for a monogamous female who intentionally gets into relationships with males who are in polyamorous relationships. The female gets into these relationships with the goal of extracting the male from his other partners and securing him in a monogamous relationship.
A polyamorous female will sometimes become a Cowgirl by accident when she falls for a polyamorous male.
The male counterpart for this term is Cowboy.
Justin warned his polyamorous friend Alex about Hailey, who he'd just met.
“Be careful around Hailey, I heard that she's a Cowgirl, she's gonna try and steal you for herself!”
“No way could happen; this stallion was born free.” Alex replied.
Three weeks later Alex and Hailey were married with two cats.