Source : Webster's Revised Unabridged Dictionary (1913)

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

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

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

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

            Equality of two domestic powers Breed scrupulous
            faction.                              --Shak.

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

            The justice of that cause ought to be evident; not
            obscrure, not scrupulous.             --Bacon.

   Syn: Cautious; careful; conscientious; hesitating. --
        {Scru"pu*lous*ly}, adv. -- {Scru"pu*lous*ness}, n.

Source : WordNet®

scrupulous
     adj 1: having scruples; arising from a sense of right and wrong;
            principled; "less scrupulous producers sent bundles
            that were deceptive in appearance" [ant: {unscrupulous}]
     2: characterized by extreme care and great effort;
        "conscientious application to the work at hand";
        "painstaking research"; "scrupulous attention to details"
        [syn: {conscientious}, {painstaking}]