From AnthroWiki

Atziluth or Azilut (Hebrewאֲצִילוּת "nobility, sublimity, goodness, nobility"; also Olam Atziluth, עולם אצילות the "world of sublimity") is, according to the Jewish Kabbalah, the uppermost of the four worlds and comprises the uppermost three Sefirot Keter (crown), Chokmah (wisdom) and Binah (understanding). It corresponds to the Devachan respectively to the Higher Devachan according to theosophical-anthroposophical terminology.

Atziluth corresponds to the first letter, Jod (י), of the tetragrammaton JHVH (יהוה Yahweh).