noun
hemichordate
A worm-like marine invertebrate of the phylum Hemichordata; a technical zoological term.
半索動物は、ギボシムシやフサカツギを含む海産無脊椎動物の一群です。
Hemichordates are a group of marine invertebrates that includes acorn worms and pterobranchs.
From 半 (half) + 索 (cord) + 動物 (animal), referring to the rudimentary notochord-like structure (stomochord) once thought to be a half or partial notochord.