dispute

dispute 1

•  noun [C,U]
• 

1    a serious argument or disagreement:
?a pay dispute
?be in dispute (with sb):
Some of the players are in dispute with club owners.
2    be open to dispute to not be completely certain:
?The results of this research are still open to dispute.

dispute 2

•  verb

[T] to say that you think something is not correct or true:
?The main facts of Morton's book have never been disputed.