Mŏn/o-cār'di-an1, a.
a. [Gr. μόνος, single, and καρδία, heart.] Having a single heart, as fishes and reptiles.
2 entries under this word
Monocardian
Mōn'o-cär'di-an2, n.
n. (Zoöl.) An animal having a single heart, as fishes and reptiles.