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"
earnest and conscientious activity intended to do or accomplish something; "made an effort to cover all the reading material"; "wished him luck in his endeavor"; "she gave it a good try"