ready and able to resort to force or violence; "pugnacious spirits...lamented that there was so little prospect of an exhilarating disturbance"- Herman Melville; "they were rough and determined fighting men"
spread or diffuse through; "An atmosphere of distrust has permeated this administration"; "music penetrated the entire building"; "His campaign was riddled with accusations and personal attacks"
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"
characterized by undue haste and lack of thought or deliberation; "a hotheaded decision"; "liable to such impulsive acts as hugging strangers"; "an impetuous display of spending and gambling"; "madcap escapades"; (`brainish' is archaic)