trustbuster

1. (chiefly US) A person or entity responsible for breaking up trusts or monopolies.Examples: "America’s top trustbusters mean to make their policing presence felt. Lawyers, bankers and financiers now “recognise that there are cops on the beat…that we’re vigorously looking to protect the American public from illegal mergers,” says Lina Khan, chair of the Federal Trade Commission (FTC), which enforces consumer-protection and competition laws."; "Britain’s chief trustbuster is sitting in a meeting room at the CMA’s head office after a whirlwind morning of broadcast interviews about its latest intervention, this time in the market for baby milk formula."US