/ek'ee yoor"id/ , n.
any of various unsegmented marine worms of the phylum Echiura, comprising the spoonworms.
[ Echiurida, var. of Echiura échi ( s ) viper + -oura neut. pl. of -ouros -tailed (deriv. of ourá tail); Cf. Echiurus a genus of the phylum; see -IDA ]