The Collaborative International Dictionary of English v.0.48:

Syndicalism \Syn"dic*al*ism\, n. [F. syndicalisme.]
   The theory, plan, or practice of trade-union action
   (originally as advocated and practiced by the French
   Conf['e]d['e]ration G['e]n['e]rale du Travail) which aims to
   abolish the present political and social system by means of
   the general strike (as distinguished from the local or
   sectional strike) and direct action of whatever kind (as
   distinguished from action which takes effect only through the
   medium of political action) -- direct action including any
   kind of action that is directly effective, whether it be a
   simple strike, a peaceful public demonstration, sabotage, or
   revolutionary violence. By the general strike and direct
   action syndicalism aims to establish a social system in which
   the means and processes of production are in the control of
   local organizations of workers, who are manage them for the
   common good.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

syndicalism
    n 1: a radical political movement that advocates bringing
         industry and government under the control of labor unions

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "syndicalism":
   Bolshevikism, Bolshevism, Carbonarism, Castroism, Jacobinism,
   Maoism, New Left, Old Left, Sinn Feinism, anarchism,
   anarcho-syndicalism, anarchy, antinomianism, chaos, confusion,
   criminal syndicalism, disorder, disorderliness, disorganization,
   disruption, extreme left, extreme left wing, extremism,
   left-wing extremism, lynch law, misrule, mob law, mob rule,
   mobocracy, nihilism, ochlocracy, primal chaos, radicalism,
   radicalization, rebellion, revolution, revolutionism,
   sans-culotterie, sans-culottism, terrorism, tohubohu, turmoil,
   ultraconservatism, ultraism, unruliness