adjective (a)

• not fair; marked by injustice or partiality or deception(adj.all)

  Synonym:
  unfair
  Antonym:
  fair, just
  

  source: wordnet30
• violating principles of justice(adj.all)

  Example:
  Unjust punishment.
  An unjust judge.
  An unjust accusation.
  

  Antonym:
  just
  

  source: wordnet30
• not equitable or fair(adj.all)

  Synonym:
  inequitable
  Antonym:
  equitable, just
  

  source: wordnet30
• Acting contrary to the standard of right; not animated or controlled by justice; false; dishonest; as, an unjust man or judge.(adjective)

  source: webster1913