Hĕc'to-cōt'y-lŭs, n.

n. [Gr. ἐκτός, out of, or separate from, and κοτύλη, a small cup.] (Physiol.) The arm of a kind of cuttle-fish, which takes on a modified form, and bears the male generative organs, and which separates from the male so as to swim free, in which state it performs its appointed functions.

Carpenter.