involving or likely to cause controversy; "a central and contentious element of the book"- Tim W.Ferfuson
inclined or showing an inclination to dispute or disagree, even to engage in law suits; "a style described as abrasive and contentious"; "a disputatious lawyer"; "a litigious and acrimonious spirit"
a disagreement or argument about something important; "he had a dispute with his wife"; "there were irreconcilable differences"; "the familiar conflict between Republicans and Democrats"