hemichordate
noun
hemi·chor·date ˌhe-mi-ˈkȯr-dət 
-ˈkȯr-ˌdāt
: any of a phylum (Hemichordata) of wormlike marine animals (such as an acorn worm) that have in the proboscis an outgrowth of the pharyngeal wall which superficially resembles the notochord of chordates
Word History
Etymology
New Latin Hemichordata, from hemi- + Chordata chordates
First Known Use
1885, in the meaning defined above