Main definitions of isis in US English:

: Isis1Isis2ISIS3

Isis1

proper noun

Egyptian Mythology
  • A goddess of fertility, wife of Osiris and mother of Horus. Her worship spread to western Asia, Greece, and Rome, where she was identified with various local goddesses.

Pronunciation

Isis

/ˈīsis//ˈaɪsɪs/

Main definitions of isis in US English:

: Isis1Isis2ISIS3

Isis2

proper noun

  • A name for the part of the River Thames that flows through Oxford, England.

Origin

From Latin Tamesis, the Roman name for the Thames, of Celtic origin.

Pronunciation

Isis

/ˈīsis//ˈaɪsɪs/

Main definitions of isis in US English:

: Isis1Isis2ISIS3

ISIS3

(also Isis)

proper noun

  • A militant Islamic fundamentalist group active particularly in Syria and Iraq.

    Also called ISIL, Islamic State

Origin

Early 21st century: acronym from Islamic State in Iraq and Syria or Islamic State in Iraq and al-Sham (‘Syria’ or ‘the Levant’).

Pronunciation

ISIS

/ˈīsis//ˈaɪsɪs/