Un-warranted refers to something that is not justified or authorized. Its antonyms are warranted, authorized, justified, valid, legitimate, reasonable, and rightful. Warranted means deserving or justifying something, and authorized refers to something that has official approval or permission. Justified means having a valid reason or showing that something is right or reasonable, while valid refers to something that is logical, legally binding, or acceptable. Legitimate means conforming to the law or to rules, rightful refers to something that is due to a person or is morally justified, and reasonable means sensible or fair. The antonyms of unwarranted represent a situation or argument that is valid, justifiable, and fair.