The Collaborative International Dictionary of English v.0.48:

Sorcery \Sor"cer*y\, n.; pl. Sorceries. [OE. sorcerie, OF.
   sorcerie, fr. OF. & F. sorcier a sorcerer, LL. sortiarius,
   fr. L. sors, sortis, a lot, decision by lot, fate, destiny.
   See Sort, n.]
   Divination by the assistance, or supposed assistance, of evil
   spirits, or the power of commanding evil spirits; magic;
   necromancy; witchcraft; enchantment.
   [1913 Webster]

         Adder's wisdom I have learned,
         To fence my ear against thy sorceries.   --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sorcery
    n 1: the belief in magical spells that harness occult forces or
         evil spirits to produce unnatural effects in the world
         [syn: sorcery, black magic, black art, necromancy]

The Devil's Dictionary (1881-1906):

SORCERY, n.  The ancient prototype and forerunner of political
influence.  It was, however, deemed less respectable and sometimes was
punished by torture and death.  Augustine Nicholas relates that a poor
peasant who had been accused of sorcery was put to the torture to
compel a confession.  After enduring a few gentle agonies the
suffering simpleton admitted his guilt, but naively asked his
tormentors if it were not possible to be a sorcerer without knowing
it.