ˌɡʊd ˈlʌk ˈtrɛm.ə.təʊd ˈtrɛm.əˌtoʊd parasitic flatworms having external suckers for attaching to a host either of the two lobes of the tail of a cetacean flat bladelike projection on the arm of an anchor a barb on a harpoon or arrow a stroke of luck