based on or subject to individual discretion or preference or sometimes impulse or caprice; "an arbitrary decision"; "the arbitrary rule of a dictator"; "an arbitrary penalty"; "of arbitrary size and shape"; "an arbitrary choice"; "arbitrary division of the group into halves"
unpredictably difficult in operation; likely to be troublesome; "rockets were much too fractious to be tested near thickly populated areas"; "fractious components of a communication system"
stubbornly resistant to authority or control; "a fractious animal that would not submit to the harness"; "a refractory child"