The Collaborative International Dictionary of English v.0.48:

Guiltless \Guilt"less\, a.
   1. Free from guilt; innocent.
      [1913 Webster]

            The Lord will not hold him guiltless that taketh his
            name in vain.                         --Ex. xx. 7.
      [1913 Webster]

   2. Without experience or trial; unacquainted (with).
      [1913 Webster]

            Such gardening tools, as art, yet rude,
            Guiltless of fire, had formed.        --Milton.
      -- Guilt"less*ly, adv. -- Guilt"less*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

guiltless
    adj 1: free from evil or guilt; "an innocent child"; "the
           principle that one is innocent until proved guilty" [syn:
           innocent, guiltless, clean-handed] [ant: guilty]