Real Dictionary

Isis in American English
noun: a goddess of fertility, the sister and wife of Osiris and mother of Horus, and usually represented as a woman with a cow's horns with the solar disk between them: later worshiped in the Greek and Roman empires

Isis in American English 1
the goddess of fertility, sister and wife of Osiris, usually represented with a cow's horns surrounding a solar (or lunar) disk

Isis in American English 2
Thames , esp. at, & west of, Oxford

ISIS in British English
noun acronym for: Islamic State of Iraq and Syria

Isis in British English 1
noun: the local name for the River Thames at Oxford

Isis in British English 2
noun: an ancient Egyptian fertility goddess, depicted as a woman with a cow's horns, between which was the disc of the sun; wife and sister of Osiris