Words related to an-
1530s, "absence of government," from French anarchie or directly from Medieval Latin anarchia, from Greek anarkhia "lack of a leader, the state of people without a government" (in Athens, used of the Year of Thirty Tyrants, 404 B.C., when there was no archon), abstract noun from anarkhos "rulerless," from an- "without" (see an- (1)) + arkhos "leader" (see archon).
From 1660s as "confusion or absence of authority in general;" by 1849 in reference to the social theory advocating "order without power," with associations and co-operatives taking the place of direct government, as formulated in the 1830s by French political philosopher Pierre-Joseph Proudhon (1809-1865).
Either the State for ever, crushing individual and local life, taking over in all fields of human activity, bringing with it its wars and its domestic struggles for power, its palace revolutions which only replace one tyrant by another, and inevitably at the end of this development there is ... death! Or the destruction of States, and new life starting again in thousands of centers on the principle of the lively initiative of the individual and groups and that of free agreement. The choice lies with you! [Prince Peter Kropotkin (1842-1921), "The State: Its Historic Role," 1896]
Procopius' 6c. Anecdota, unpublished memoirs of Emperor Justinian full of court gossip, gave the word a sense of "revelation of secrets," which decayed in English to "brief, amusing story" (1761).
"having no brain" (biology), 1821, with -ic + Latinized form of Greek anenkephalos, from an- "not, without" (see an- (1)) + enkephalos "brain," "the brain," literally "within the head," from en "in" (see en- (2)) + kephalē "head;" see cephalo-. Related: Anencephalous (1834); anencephalia; anencephaly.
1721, "loss of feeling," medical Latin, from Greek anaisthēsia "want of feeling or perception, lack of sensation (to pleasure or pain)," abstract noun from an- "without" (see an- (1)) + aisthēsis "feeling," from PIE root *au- "to perceive." For the abstract noun ending, see -ia. As "a procedure for the prevention of pain in surgical operations," from 1846. Aesthesia "capacity for feeling" is attested in English from 1853, perhaps a back-formation.