Dictionary.net

[Gr.] (Ichth.) Gen. of small fish with bony covering, prehensile tail, horse-like head. One spec. found on British coasts, more in Mediterranean Sea and Atlantic; most in Indian and Pacific Oceans. Fam. Syngnathidae, ord. Lophobranchii, sub-class Teleostei.

n. The walrus;—the hippopotamus or river-horse;—a fish allied to the pipe-fish, and having a prehensile tail.