The Collaborative International Dictionary of English v.0.48:

Absolutism \Ab"so*lu`tism\, n.
   1. The state of being absolute; the system or doctrine of the
      absolute; the principles or practice of absolute or
      arbitrary government; despotism.
      [1913 Webster]

            The element of absolutism and prelacy was
            controlling.                          --Palfrey.
      [1913 Webster]

   2. (Theol.) Doctrine of absolute decrees. --Ash.
      [1913 Webster]

WordNet (r) 3.0 (2006):

absolutism
    n 1: dominance through threat of punishment and violence [syn:
         absolutism, tyranny, despotism]
    2: a form of government in which the ruler is an absolute
       dictator (not restricted by a constitution or laws or
       opposition etc.) [syn: dictatorship, absolutism,
       authoritarianism, Caesarism, despotism, monocracy,
       one-man rule, shogunate, Stalinism, totalitarianism,
       tyranny]
    3: the principle of complete and unrestricted power in
       government [syn: absolutism, totalitarianism, totalism]
    4: the doctrine of an absolute being

Moby Thesaurus II by Grady Ward, 1.0:

70 Moby Thesaurus words for "absolutism":
   Caesarism, Stalinism, absolute monarchy, absolute power, autarchy,
   authoritarianism, authority, autocracy, benevolent despotism,
   bond service, bondage, captivity, competence, competency,
   constituted authority, control, czarism, debt slavery,
   delegated authority, deprivation of freedom, despotism,
   dictatorship, disenfranchisement, disfranchisement, divine right,
   domination, enslavement, enthrallment, faculty, feudalism,
   feudality, helotism, helotry, indentureship, indirect authority,
   inherent authority, jus divinum, kaiserism, lawful authority,
   legal authority, legitimacy, monarchy, one-man rule,
   one-party rule, paternalism, peonage, power, prerogative, regality,
   restraint, right, rightful authority, royal prerogative, serfdom,
   serfhood, servility, servitude, slavery, subjection, subjugation,
   the say, the say-so, thrall, thralldom, totalitarianism, tyranny,
   vassalage, vested authority, vicarious authority, villenage