mis·be·lief \|misbə̇|lēf, -spə̇-\noun Etymology: alteration of Middle English misbileve, misbileave, from mis- (I) + beleve, beleave belief — more at belief 1.: religious belief regarded as false or unorthodox : heresy < tried to convert him from his misbelief > 2.: opinion or doctrine thought to be false < the misbeliefs and unscientific notions of prehistoric man >