Meaning

noun a state in the Rocky Mountains

noun a card or badge used to identify the bearer

noun (psychoanalysis) primitive instincts and energies underlying all psychic activity

originFrom New Latin id (“it”), chosen by Freud’s translator as a translation of his use of German Es (“it”) as a noun for this concept from the pronoun es (“it”).

Etymology from Wiktionary, CC BY-SA 3.0