acorn worm
Refers to any hemichordate of the class Enteropneusta. A technical term in zoology; in everyday contexts, it is rarely encountered.
I found acorn worm burrows on the tidal flat.
Acorn worms are classified as hemichordates.
Standard katakana spelling for this organism.
Kanji spelling is rare and mainly used in scientific contexts; the word is usually written in kana.
The name ギボシムシ comes from the shape of the proboscis, which resembles a 擬宝珠 (giboshi), a traditional ornamental cap on bridge posts and railings. The derivation is straightforward, but the word is a modern coinage for this animal group.