Is it ensure, insure, or assure?
1755, "chaotic, without order or rule," from Greek anarkhos "without head or chief" (see anarchy) + -ic. Differentiated from anarchistic (1845) which tends to refer to the political philosophy of anarchism. An older word in this sense was anarchical (1590s). Anarchial is from 1710; Landor used anarchal (1824).