term:

Capricious

capricious adj

1 : governed or characterized by impulse or whim: as
a : lacking a rational basis
b : likely to change suddenly
2 : not supported by the weight of evidence or established rules of law often used in the phrase arbitrary and capricious
ca·pri·cious·ly adv

ca·pri·cious·ness n

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.