Māyā  is derived from the root √ma : means – to measure, to form, to limit . In the Vedāntic tradition it means specifically , “the illusion superimposed upon reality as an effect of ignorance.” Later Śankara describes the entire visible cosmos as māyā, an illusion superimposed upon true being by man’s deceitful senses & unilluminated mind .
Māyā is the measuring out, or creation, or display of forms; māyā is any illusion, trick, artifice, deceit, jugglery, sorcery, or work of witch-craft; an illusory image or apparition, phantasm, deception of the sight….The māyā of the Gods is their power to assume diverse shapes by displaying at will various aspects of their subtle essence. But the Gods are themselves the productions of a greater Māyā : the spontaneous self-transformation of an originally undifferentiated, all-generating divine Substance. And this greater Māyā produces, not the Gods alone, but the Universe in which they operate. All the Universes co-existing in space and succeeding each other in time, the planes of being and the creatures of those planes whether natural or supernatural, are manifestations from an inexhaustible, original and eternal well of being, and are manifest by a play of māyā. In the period of non-manifestation, the interlude of the cosmic night, māyā ceases to operate and the display dissolves.