Noun | 1. | Filariidae - threadlike roundworms worm family - a family of worms Aschelminthes, Nematoda, phylum Aschelminthes, phylum Nematoda - unsegmented worms: roundworms; threadworms; eelworms filaria - slender threadlike roundworms living in the blood and tissues of vertebrates; transmitted as larvae by biting insects |