The Collaborative International Dictionary of English v.0.48:

Scrupulous \Scru"pu*lous\, a. [L. scrupulosus: cf. F.
   scrupuleux.]
   1. Full of scruples; inclined to scruple; nicely doubtful;
      hesitating to determine or to act, from a fear of
      offending or of doing wrong.
      [1913 Webster]

            Abusing their liberty, to the offense of their weak
            brethren which were scrupulous.       --Hooker.
      [1913 Webster]

   2. Careful; cautious; exact; nice; as, scrupulous abstinence
      from labor; scrupulous performance of duties.
      [1913 Webster]

   3. Given to making objections; captious. [Obs.]
      [1913 Webster]

            Equality of two domestic powers
            Breed scrupulous faction.             --Shak.
      [1913 Webster]

   4. Liable to be doubted; doubtful; nice. [Obs.]
      [1913 Webster]

            The justice of that cause ought to be evident; not
            obscure, not scrupulous.              --Bacon.
      [1913 Webster]

   Syn: Cautious; careful; conscientious; hesitating.
        [1913 Webster] -- Scru"pu*lous*ly, adv. --
        Scru"pu*lous*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

scrupulousness
    n 1: conformity to high standards of ethics or excellence [ant:
         unscrupulousness]
    2: strict attention to minute details [syn: meticulousness,
       meticulosity, punctiliousness, scrupulousness]