The Collaborative International Dictionary of English v.0.48:

Toleration \Tol`er*a"tion\, n. [L. toleratio: cf. OF.
   toleration.]
   1. The act of tolerating; the allowance of that which is not
      wholly approved.
      [1913 Webster]

   2. Specifically, the allowance of religious opinions and
      modes of worship in a state when contrary to, or different
      from, those of the established church or belief.
      [1913 Webster]

   3. Hence, freedom from bigotry and severity in judgment of
      the opinions or belief of others, especially in respect to
      religious matters.
      [1913 Webster]

WordNet (r) 3.0 (2006):

toleration
    n 1: a disposition to tolerate or accept people or situations;
         "all people should practice toleration and live together in
         peace" [syn: toleration, acceptance, sufferance]
    2: official recognition of the right of individuals to hold
       dissenting opinions (especially in religion)