Wordnet 3.0
ADVERB (1)
1. 
 in an unjust manner; 
- Example: "he was unjustly singled out for punishment"
The Collaborative International Dictionary of English v.0.48:
Unjust \Un*just"\, a.
   1. Acting contrary to the standard of right; not animated or
      controlled by justice; false; dishonest; as, an unjust man
      or judge.
      [1913 Webster]
   2. Contrary to justice and right; prompted by a spirit of
      injustice; wrongful; as, an unjust sentence; an unjust
      demand; an unjust accusation.
      [1913 Webster] -- Un*just"ly, adv. -- Un*just"ness, n.
      [1913 Webster]
WordNet (r) 3.0 (2006):
unjustly
    adv 1: in an unjust manner; "he was unjustly singled out for
           punishment" [ant: justifiedly, justly, rightly]