flashlight fish flash·light·fish uncommon noun 1. fish of deep dark waters having a light organ below each eye Synonymsflashlight fishPhotoblepharon palpebratus 2. fish having a luminous organ beneath eye; of warm waters of the western Pacific and Puerto Rico Synonymsanomalopsflashlight fish Related words Broader terms spiny-finned fish Parts genus Anomalops WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.