na-adjective, noun which may take the genitive case particle 'no', noun
Describes actions, organizations, or items that are against the law. Often used in formal or legal contexts, contrasting with 違法 (which can imply a clearer violation of specific statutes).
You must not earn money by illegal means.
その組織は非合法活動に関与していた。
The organization was involved in unlawful activities.
In that country, illegal weapons trading is a problem.
He had obtained drugs illegally.
The government outlawed the organization.