Pronunciation: ˌ e-ki- ' yu ̇ r- ˌ o ̇ id
Function: noun
Etymology: New Latin Echiuroidea or Echiura, ultimately from Greek echis viper + oura tail
Date: circa 1889
: any of a phylum (Echiura syn. Echiuroidea) of marine worms of uncertain taxonomic affinities that have a sensitive but nonretractile proboscis above the mouth