ar·gu·able
 /ˈɑɚgjuwəbəl/  adj  
  1 : not certain or clearly true : open to argument, dispute, or question
   That word's pronunciation is arguable.
   the arguable [=questionable] benefits of trying to follow every fad diet
   That is an arguable point of view.
  2 : possibly true
  — used to say that there are good reasons for believing that a statement is true
   It is arguable that he's the best writer of his generation.