Definition of echiuroid
: any of a phylum (Echiura synonym Echiuroidea) of marine worms of uncertain taxonomic affinities that have a sensitive but nonretractile proboscis above the mouth
Origin and Etymology of echiuroid
New Latin Echiuroidea or Echiura, ultimately from Greek echis viper + oura tail
First Known Use: circa 1889
Seen and Heard
What made you want to look up echiuroid? Please tell us where you read or heard it (including the quote, if possible).