Hĕt'er-o-pōd, n.

noun

n. [Fr. hétéropode, from Gr. ἕτερος, other, and πούς, ποδός, foot.] (Zoöl.) One of an order of molluscous animals whose foot is compressed into a vertical, muscular lamina, serving for a fin. [Obs.]

An illustration of a heteropod mollusk with a coiled shell and an extended body and appendages.
Heteropod.