AVIDYA

Avidyā is a Sanskrit word meaning Ignorance, delusion, unlearned, unwise. It is used extensively in Hindu texts, including the Upanishads.
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Avidya (Sanskrit) [from a not + vidya knowledge, wisdom] Nescience rather than ignorance; it implies absence of wisdom rather than inherent incapacity, and is the result of illusion producing ignorance. Hence ignorance of spiritual things. See also Vidya

Avidya literally means "ignorance," and is the opposite of Vidya . It can refer to ignorance of proper social and religious behavior. In Sankara's thought (preserved in Advaita Vedanta), it became more than that. Avidya is the delusion of both the intellect and the spirit. This delusion prevents one from seeing beyond the duality of this world (i.e., matter) into the true unity of everything.