陥かん入にゅう吻ふんかんにゅうふんMeanings1nounintrovert; eversible proboscisbiology›A biological term for a retractable, tube-like feeding structure found in certain invertebrates, especially sipunculans (peanut worms).ホシムシの陥かん入にゅう吻ふんは、餌えさを捕とらえる