noun
introvert; eversible proboscis
A biological term for a retractable, tube-like feeding structure found in certain invertebrates, especially sipunculans (peanut worms).
ホシムシの陥入吻は、餌を捕らえるために体外に伸ばされる。
The introvert of a peanut worm is extended outside the body to capture food.
The term is composed of 陥入 (かんにゅう, 'invagination' or 'retraction') and 吻 (ふん, 'proboscis'), describing a retractable proboscis. The exact historical derivation is uncertain; it is a technical compound used in zoology.