antitrust Syllabification: (an·ti·trust)Pronunciation: /ˌantēˈtrəst, ˌantī-/Translate antitrust | into Italian Definition of antitrust adjective [attributive] of or relating to legislation preventing or controlling trusts or other monopolies, with the intention of promoting competition in business. antitrust in other Oxford dictionaries Definition of antitrust in the British & World English dictionary