adjective (a)

• (of characters in literature or drama) tending to evoke antipathetic feelings(adj.all)

  Synonym:
  unlikable, unlikeable, unsympathetic
  Antonym:
  appealing, likable, likeable, sympathetic
  

  source: wordnet30
• not able to attract favorable attention(adj.all)

  Example:
  They have made the place as unappealing as possible.
  Was forced to talk to his singularly unappealing hostess.
  

  Antonym:
  appealing
  

  source: wordnet30