The Collaborative International Dictionary of English v.0.48:

Belief \Be*lief"\, n. [OE. bileafe, bileve; cf. AS. gele['a]fa.
   See Believe.]
   1. Assent to a proposition or affirmation, or the acceptance
      of a fact, opinion, or assertion as real or true, without
      immediate personal knowledge; reliance upon word or
      testimony; partial or full assurance without positive
      knowledge or absolute certainty; persuasion; conviction;
      confidence; as, belief of a witness; the belief of our
      senses.
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            Belief admits of all degrees, from the slightest
            suspicion to the fullest assurance.   --Reid.
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   2. (Theol.) A persuasion of the truths of religion; faith.
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            No man can attain [to] belief by the bare
            contemplation of heaven and earth.    --Hooker.
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   3. The thing believed; the object of belief.
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            Superstitious prophecies are not only the belief of
            fools, but the talk sometimes of wise men. --Bacon.
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   4. A tenet, or the body of tenets, held by the advocates of
      any class of views; doctrine; creed.
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            In the heat of persecution to which Christian belief
            was subject upon its first promulgation. --Hooker.
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   Ultimate belief, a first principle incapable of proof; an
      intuitive truth; an intuition. --Sir W. Hamilton.
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   Syn: Credence; trust; reliance; assurance; opinion.
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WordNet (r) 3.0 (2006):

belief
    n 1: any cognitive content held as true [ant: disbelief,
         unbelief]
    2: a vague idea in which some confidence is placed; "his
       impression of her was favorable"; "what are your feelings
       about the crisis?"; "it strengthened my belief in his
       sincerity"; "I had a feeling that she was lying" [syn:
       impression, feeling, belief, notion, opinion]

Moby Thesaurus II by Grady Ward, 1.0:

73 Moby Thesaurus words for "belief":
   a belief, acceptance, acquiescence, arrogance, article of faith,
   assent, assurance, assuredness, axiom, canon, certainty, certitude,
   cocksureness, concept, confidence, confidentness, conviction,
   courage, credence, credibility, credit, credo, creed, dependence,
   doctrine, dogma, eye, faith, feeling, fundamental, hubris, idea,
   intuition, judgement, law, maxim, mind, opinion, orthodoxy,
   overconfidence, oversureness, overweening, overweeningness,
   persuasion, poise, pomposity, positiveness, precept, pride,
   principle, principles, reliance, religion, religious belief,
   religious faith, security, self-assurance, self-confidence,
   self-importance, self-reliance, sentiment, settled belief,
   subjective certainty, sureness, surety, system of beliefs,
   teaching, tenet, theology, tradition, trust, trustworthiness,
   view



Bouvier's Law Dictionary, Revised 6th Ed (1856):

BELIEF. The conviction of the mind, arising from evidence received, or from
information derived, not from actual perception by our senses, but from. the
relation or information of others who have had the means of acquiring actual
knowledge of the facts and in whose qualifications for acquiring that
knowledge, and retaining it, and afterwards in communicating it, we can
place confidence. " Without recurring to the books of metaphysicians' "says
Chief Justice Tilghman, 4 Serg. & Rawle, 137, "let any man of plain common
sense, examine the operations of, his own mind, he will assuredly find that
on different subjects his belief is different. I have a firm belief that,
the moon revolves round the earth. I may believe, too, that there are
mountains and valleys in the moon; but this belief is not so strong, because
the evidence is weaker." Vide 1 Stark. Ev. 41; 2 Pow. Mortg. 555; 1 Ves. 95;
12 Ves. 80; 1 P. A. Browne's R 258; 1 Stark. Ev. 127; Dyer, 53; 2 Hawk. c.
46, s. 167; 3 Wil. 1, s. 427; 2 Bl. R. 881; Leach, 270; 8 Watts, R. 406; 1
Greenl. Ev. Sec. 7-13, a.