The name is variously written “da-nuna”, “da-nuna-ke4-ne”, or “da-nun-na”, meaning “princely offspring” or “offspring of Anu”. According to The Oxford Companion to World Mythology, the Anunnaki: “…are the Sumerian deities of the old primordial line; they are chthonic deities of fertility, associated eventually with the underworld, where they became judges. They take their name from the old sky god An (Anu).”
By her consort Anu, Ki gave birth to the Anunnaki, the most prominent of these deities being Enlil, god of the air. According to legends, heaven and earth were once inseparable until Enlil was born; Enlil cleaved heaven and earth in two. An carried away heaven. Ki, in company with Enlil, took the earth.
Some authorities question whether Ki was regarded as a deity since there is no evidence of a cult and the name appears only in a limited number of Sumerian creation texts. Samuel Noah Kramer identifies Ki with the Sumerian mother goddess Ninhursag and claims that they were originally the same figure.