A company, party, assembly, group, club or gathering that is dominated/staffed largely by men. See "sausage fest".
We showed up during Ladies Night, but sadly it turned out to be largely a manopoly.
/man•op'•pO•lee/ n. the situation of being the only single, straight male in a large group, especially in the workplace.
Jay: Is the new guy in the Compliance department married or gay?
Jay: Cuz I like being the only straight, single guy in this company. Lots of pretty girls here, and only me to flirt with.
Paige: that's creepy.
Rick: No, he's just trying to protect his manopoly.