dilated di·la·ted UK/daɪˈleɪtɪd/ US/ˌdaɪˈleɪtɪd/ uncommon adjective 1. made wider or larger in all dimensions “a dilated pupil” Similarexpanded WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved.