The Collaborative International Dictionary of English v.0.48:

distrust \dis*trust"\, v. t. [imp. & p. p. Distrusted; p. pr.
   & vb. n. Distrusting.] [Cf. Mistrust.]
   To feel absence of trust in; not to confide in or rely upon;
   to deem of questionable sufficiency or reality; to doubt; to
   be suspicious of; to mistrust.
   [1913 Webster]

         Not distrusting my health.               --2 Mac. ix.
                                                  22.
   [1913 Webster]

         To distrust the justice of your cause.   --Dryden.
   [1913 Webster]

         He that requireth the oath doth distrust that other.
                                                  --Udall.
   [1913 Webster]

         Of all afraid,
         Distrusting all, a wise, suspicious maid. --Collins.
   [1913 Webster]

   Note: Mistrust has been almost wholly driven out by distrust.
         --T. L. K. Oliphant.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

distrust \dis*trust"\, n.
   1. Doubt of sufficiency, reality, or sincerity; lack of
      confidence, faith, or reliance; as, distrust of one's
      power, authority, will, purposes, schemes, etc.
      [1913 Webster]

   2. Suspicion of evil designs.
      [1913 Webster]

            Alienation and distrust . . . are the growth of
            false principles.                     --D. Webster.
      [1913 Webster]

   3. State of being suspected; loss of trust. --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

distrust
    n 1: doubt about someone's honesty [syn: misgiving,
         mistrust, distrust, suspicion]
    2: the trait of not trusting others [syn: distrust,
       distrustfulness, mistrust] [ant: trust, trustfulness,
       trustingness]
    v 1: regard as untrustworthy; regard with suspicion; have no
         faith or confidence in [syn: distrust, mistrust,
         suspect] [ant: bank, rely, swear, trust]

Moby Thesaurus II by Grady Ward, 1.0:

60 Moby Thesaurus words for "distrust":
   Pyrrhonism, apprehension, awake a doubt, be diffident, be doubtful,
   be dubious, be possessive, be skeptical, be uncertain, cageyness,
   call in question, caution, challenge, chariness, contest,
   diffidence, disbelief, disbelieve, discredit, dispute,
   distrustfulness, doubt, doubtfulness, dubiety, dubiousness,
   greet with skepticism, half believe, half-belief,
   harbor suspicions, have reservations, hesitancy, hesitation,
   incredulity, leeriness, misdoubt, misgive, misgiving, mistrust,
   mistrustfulness, qualm, query, question, raise a question,
   scepticism, scruple, scrupulousness, self-doubt, shadow of doubt,
   skepticalness, skepticism, smell a rat, suspect, suspicion,
   suspiciousness, throw doubt upon, total skepticism,
   treat with reserve, unbelieve, uncertainty, wariness