The Collaborative International Dictionary of English v.0.48:

Persuasion \Per*sua"sion\, n. [L. persuasio; Cf. F. persuasion.]
   1. The act of persuading; the act of influencing the mind by
      arguments or reasons offered, or by anything that moves
      the mind or passions, or inclines the will to a
      determination.
      [1913 Webster]

            For thou hast all the arts of fine persuasion.
                                                  --Otway.
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   2. The state of being persuaded or convinced; settled opinion
      or conviction, which has been induced.
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            If the general persuasion of all men does so account
            it.                                   --Hooker.
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            My firm persuasion is, at least sometimes,
            That Heaven will weigh man's virtues and his crimes
            With nice attention.                  --Cowper.
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   3. A creed or belief; a sect or party adhering to a certain
      creed or system of opinions; as, of the same persuasion;
      all persuasions are agreed.
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            Of whatever state or persuasion, religious or
            political.                            --Jefferson.
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   4. The power or quality of persuading; persuasiveness.
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            Is 't possible that my deserts to you
            Can lack persuasion?                  --Shak.
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   5. That which persuades; a persuasive. [R.]
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   Syn: See Conviction.
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WordNet (r) 3.0 (2006):

persuasion
    n 1: the act of persuading (or attempting to persuade);
         communication intended to induce belief or action [syn:
         persuasion, suasion] [ant: dissuasion]
    2: a personal belief or judgment that is not founded on proof or
       certainty; "my opinion differs from yours"; "I am not of your
       persuasion"; "what are your thoughts on Haiti?" [syn:
       opinion, sentiment, persuasion, view, thought]

Moby Thesaurus II by Grady Ward, 1.0:

176 Moby Thesaurus words for "persuasion":
   adherents, affiliation, allurement, ascendancy, authority, belief,
   bias, blandishment, blood, body, branch, brand, breed, cajolement,
   cajolery, cast, character, charisma, charm, church, clan, class,
   clout, coaxing, color, communion, community, confession,
   connection, conning, consequence, control, conversion, conviction,
   credit, creed, cult, denomination, description, designation,
   disciples, division, dominance, domination, effect, eminence,
   enchantment, engagement, enlistment, esteem, evangelization,
   exhortation, exhorting, eye, faction, faith, favor, feather,
   feeling, fellowship, fixed opinion, followers, force, form, genre,
   genus, good feeling, grain, group, hold, hortation, ilk,
   implicit belief, importance, incidental power, inducement,
   inducing, influence, influencing, influentiality, insinuation, ism,
   jawboning, kidney, kin, kind, label, leadership, leverage, line,
   lobbying, lot, magnetism, make, manner, mark, mastery,
   mature judgment, mind, mold, moment, nature, number, offshoot,
   opinion, order, organization, partiality, party, personality,
   persuading, phylum, potency, power, preaching, preachment,
   predilection, predominance, prejudice, preponderance,
   prepossession, pressure, prestige, proselytism, proselytization,
   purchase, race, reign, religion, religious order, repute, rule,
   sales talk, salesmanship, say, schism, school, school of thought,
   sect, sectarism, segment, selling, sentiment, settled judgment,
   shape, snow job, society, soft soap, solicitation, sort, species,
   stamp, staunch belief, steadfast faith, strain, stripe, style,
   suasion, subtle influence, suggestion, supremacy, sway, sweet talk,
   the like of, the likes of, tribe, type, unshaken confidence,
   upper hand, variety, version, view, weight, wheedling, whip hand,
   working on



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

PERSUASION. The act of influencing by expostulation or request. While the
persuasion is confined within those limits which leave the mind free, it may
be used to induce another to make his will, or even to make it in his own
favor; but if such persuasion should so far operate on the mind of the
testator, that he would be deprived of a perfectly free will, it would
vitiate the instrument. 3 Serg. & Rawle, 269; 5 Serg. & Rawle, 207; 13 Serg.
& Rawle, 323.