Not natural; contrary to nature; monstrous; especially, contrary to the natural feelings: as, unnatural offenses.Acting without the affections of our common nature; not having the feelings natural to humanity; being without natural instincts: as, an unnatural parent.Not in conformity to nature; not agreeable to the real character of persons or things; not representing nature; forced; strained; affected; artificial: as, unnatural images or descriptions.=Syn. 1-3. Preternatural, etc. See supernatural.Artificial, etc. See factitious.