narc UK /ˈnɑːk/US /ˈnɑɹk/noun 2verb 1forms 3 noun2 •(informal) A police officer or federal agent assigned to or engaging in illegal narcotics control. •(informal) A narcissist. verb1 •(slang) To suffer from impaired judgment due to nitrogen narcosis (for example, while scuba diving). formsnarced · narcing · narcs