noun
lawfulness; legality; legitimacy
Refers to the quality of being in accordance with law or established rules. Often used in legal, political, and formal contexts.
この契約の合法性について弁護士に相談した。
I consulted a lawyer about the legality of this contract.
政府はその決定の合法性を主張している。
The government is asserting the legitimacy of its decision.
適法性 is a more technical legal term for 'legality' or 'conformity to law', often used in statutes and court rulings, whereas 合法性 is broader and can refer to general lawfulness or legitimacy.
Compound of 合法 (gōhō, 'legal, lawful') + 性 (-sei, '-ness, -ity'), a common pattern for forming abstract nouns from adjectival stems.