Origin: Greek prefix anti-
Antitrust has 2 different meanings across 1 category:
of laws and regulations; designed to protect trade and commerce from unfair business practices
"The company settled the antitrust lawsuit after regulators found that its exclusive contracts were stifling competition in the market."
Opposed to or against the establishment or existence of trusts (monopolies), usually referring to legislation.
"The senator introduced new antitrust measures to break up the tech giant's monopoly on online advertising."