monopolizers

Monopolizers are people or entities that take exclusive control of something, whether a market, a resource, or simply a conversation.

The term carries negative connotations, suggesting greed or unfairness in claiming more than one's share.

The monopolizers of the tech industry faced antitrust scrutiny.

In casual use, it often describes someone who dominates social situations: She's such a monopolizer of his attention that no one else can get a word in.