dobsonflyPronunciation: /ˈdɒbs(ə)nflʌɪ/Definition of dobsonfly noun (plural dobsonflies) a large grey North American winged insect related to the alderflies. Its predatory aquatic larva (the hellgrammite) is often used as fishing bait. Family Corydalidae, order Neuroptera: several genera and species, in particular Corydalis cornutus Origin: early 20th century: of unknown origindobsonfly in other Oxford dictionaries Definition of dobsonfly in the US English dictionary