The Collaborative International Dictionary of English v.0.48:

Justify \Jus"ti*fy\, v. t. [imp. & p. p. Justified; p. pr. &
   vb. n. Justifying.] [F. justifier, L. justificare; justus
   just + -ficare (in comp.) to make. See Just, a., and
   -fy.]
   [1913 Webster]
   1. To prove or show to be just; to vindicate; to maintain or
      defend as conformable to law, right, justice, propriety,
      or duty.
      [1913 Webster]

            That to the height of this great argument
            I may assert eternal providence,
            And justify the ways of God to men.   --Milton.
      [1913 Webster]

            Unless the oppression is so extreme as to justify
            revolution, it would not justify the evil of
            breaking up a government.             --E. Everett.
      [1913 Webster]

   2. To pronounce free from guilt or blame; to declare or prove
      to have done that which is just, right, proper, etc.; to
      absolve; to exonerate; to clear.
      [1913 Webster]

            I can not justify whom the law condemns. --Shak.
      [1913 Webster]

   3. (Theol.) To treat as if righteous and just; to pardon; to
      exculpate; to absolve.
      [1913 Webster]

            By him all that believe are justified from all
            things, from which ye could not be justified by the
            law of Moses.                         --Acts xiii.
                                                  39.
      [1913 Webster]

   4. To prove; to ratify; to confirm. [Obs.] --Shak.
      [1913 Webster]

   5. (Print.) To make even or true, as lines of type, by proper
      spacing; to align (text) at the left (left justify) or
      right (right justify) margins of a column or page, or at
      both margins; to adjust, as type. See Justification, 4.
      [1913 Webster]

   6. (Law)
      (a) To show (a person) to have had a sufficient legal
          reason for an act that has been made the subject of a
          charge or accusation.
      (b) To qualify (one's self) as a surety by taking oath to
          the ownership of sufficient property.
          [Webster 1913 Suppl.]

                The production of bail in court, who there
                justify themselves against the exception of the
                plaintiff.                        --Bouvier's
                                                  Law Dict.
          [Webster 1913 Suppl.]

   Syn: To defend; maintain; vindicate; excuse; exculpate;
        absolve; exonerate.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

justified \jus"ti*fied\, a. (Printing)
   Arranged and spaced so as to line up at the left side or
   right side of the printed page, or on both sides; as, left
   justified; right justified.
   [PJC]

WordNet (r) 3.0 (2006):

justified
    adj 1: having words so spaced that lines have straight even
           margins

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "justified":
   balanced, born again, circumcised, converted, defensible, deserved,
   due, earned, entitled, equitable, even, evenhanded, fair,
   fair and square, fit, good, just, justifiable, lawful, legal,
   level, meet, meet and right, merited, proper, qualified, reborn,
   redeemed, regenerate, regenerated, renewed, right,
   right and proper, rightful, saved, spiritually purified, square,
   warrantable, warranted, well-earned, well-grounded, worthy