Perseus, sei, and Perses, sis, or si, A noble knight, whiche veliuered a fayre Lady (called Andromeda) from a whale, and also slue Medusa, whiche turned men into stones. Of his fa-ther and mother looke Danaë, Also it is a signe among the starres.
Lewis and Short: Latin dictionary
Persēĭus, a, um, v. 2. Persa, A., and 1. Perseus, B. 2.