Source : Webster's Revised Unabridged Dictionary (1913)

Osiris \O*si"ris\, n. [L., fr. Gr. ?; of Egyptian origin.]
   (Myth.)
   One of the principal divinities of Egypt, the brother and
   husband of Isis. He was figured as a mummy wearing the royal
   cap of Upper Egypt, and was symbolized by the sacred bull,
   called Apis. Cf. {Serapis}. -- {O*sir"i*an}, a.

Source : WordNet®

Osiris
     n : Egyptian god of the underworld and judge of the dead;
         husband and sister of Isis; father or brother of Horus