noun, noun which may take the genitive case particle 'no'
legitimacy; validity; justifiability
Refers to the quality of being legally, morally, or logically justified. Used in formal, legal, and everyday contexts to question or assert the rightness of an action, claim, or decision.
The legitimacy of that policy is being questioned.
彼の主張には正当性がない。
His claim lacks validity.
正当性のある理由を説明してください。
Please explain a justifiable reason.