Quenya: Holy Ones, Sing.: Ainu
Spiritual (angelic) beings, rational spirits or minds without incarnation, were the "offspring of Il˙vatar's thought". Those of the Ainur who entered Eń, the World, and must bide in it till the End, being involved in Time, the series of events that complete it, are called Valar and Maiar.
...and he made first the Ainur, the Holy Ones, that were the offspring of his thought, and they were with him before aught else was made...
From: The Silmarillion