adjective (a)

• not important(adj.all)

  Example:
  A relatively unimportant feature of the system.
  The question seems unimportant.
  

  Antonym:
  important, of import
  

  source: wordnet30
• devoid of importance, meaning, or force(adj.all)

  Synonym:
  insignificant
  Antonym:
  important, significant
  

  source: wordnet30