The Collaborative International Dictionary of English v.0.48:

Innocence \In"no*cence\, n. [F. innocence, L. innocentia. See
   Innocent.]
   1. The state or quality of being innocent; freedom from that
      which is harmful or infurious; harmlessness.
      [1913 Webster]

   2. The state or quality of being morally free from guilt or
      sin; purity of heart; blamelessness.
      [1913 Webster]

            The silence often of pure innocence
            Persuades when speaking fails.        --Shak.
      [1913 Webster]

            Banished from man's life his happiest life,
            Simplicity and spotless innocence!    --Milton.
      [1913 Webster]

   3. The state or quality of being not chargeable for, or
      guilty of, a particular crime or offense; as, the
      innocence of the prisoner was clearly shown.
      [1913 Webster]

   4. Simplicity or plainness, bordering on weakness or
      silliness; artlessness; ingenuousness. --Chaucer. Shak.

   Syn: Harmlessness; innocuousness; blamelessness; purity;
        sinlessness; guiltlessness.
        [1913 Webster]

WordNet (r) 3.0 (2006):

innocence
    n 1: the quality of innocent naivete [syn: artlessness,
         innocence, ingenuousness, naturalness]
    2: the state of being unsullied by sin or moral wrong; lacking a
       knowledge of evil [syn: purity, pureness, sinlessness,
       innocence, whiteness]
    3: a state or condition of being innocent of a specific crime or
       offense; "the trial established his innocence" [ant: guilt,
       guiltiness]

Moby Thesaurus II by Grady Ward, 1.0:

92 Moby Thesaurus words for "innocence":
   agnosticism, artlessness, benignancy, benignity, blankmindedness,
   blotlessness, bluffness, bluntness, callowness, candor, chastity,
   childlikeness, cleanliness, cleanness, directness,
   empty-headedness, greenhornism, greenness, guilelessness,
   guiltlessness, harmlessness, hiatus of learning, honor,
   hurtlessness, ignorance, ignorantism, ignorantness, immaculacy,
   immaculateness, inanity, inexperience, ingenuousness,
   innocuousness, inoffensiveness, know-nothingism, knowledge-gap,
   lack of information, naiveness, naivete, naivety, nescience,
   obscurantism, openheartedness, openness, outspokenness, plainness,
   purity, rawness, sexual innocence, simpleheartedness,
   simplemindedness, simpleness, simplicity, sincerity,
   single-heartedness, single-mindedness, singleness of heart,
   snowiness, spotlessness, stainlessness, tabula rasa, taintlessness,
   trustfulness, unacquaintance, unacquaintedness, unawareness,
   unblemishedness, unblottedness, uncorruptness, undefiledness,
   unfamiliarity, unguardedness, uninjuriousness, unintelligence,
   unknowing, unknowingness, unobnoxiousness, unripeness,
   unsoiledness, unsophisticatedness, unsophistication, unspottedness,
   unstainedness, unsulliedness, unsuspiciousness, untaintedness,
   unwariness, vacuity, vacuousness, virtue, virtuousness,
   whiteness



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

INNOCENCE, The absence of guilt.
     2. The law presumes in favor of innocence, even against another
presumption of law: for example, when a woman marries a second husband
within the space of twelve months after her husband had left the country,
the presumption of innocence preponderates over the presumption of the
continuance of life. 2 B. & A. 386 3 Stark. Ev. 1249. An exception to this
rule respecting the presumption of innocence has been made in the case of
the publication of a libel, the principal being presumed to have authorized
the sale, when a libel is sold by his agent in his usual place of doing
business. 1 Russ. on Cr. 341; 10 Johns. R. 443; Bull. N. P. 6; Greenl. Ev.
Sec. 36. See 4 Nev. & M. 341; 2 Ad. & Ell. 540; 5 Barn. & Ad. 86; 1 Stark.
N. P. C. 21; 2 Nov. & M. 219.