na-adjective, noun
outrageous; lawless; unpardonable
Describes behavior that is morally unacceptable, insolent, or beyond the bounds of decency. Often used in formal or written contexts.
彼の不埒な態度には我慢できない。
I cannot tolerate his outrageous attitude.
その不埒な行為は決して許されない。
Such lawless conduct will never be forgiven.
Compound of 不 (not) and 埒 (bounds, limits), literally 'without bounds', referring to behavior that exceeds acceptable limits.