1.
immorality; immoral; unethical
Behavior or conduct that violates moral standards or social norms. Used both as a noun and as a な-adjective.
それは不道徳な行為だ。
That is an immoral act.
不道徳な行動は社会から批判される。
Immoral behavior is criticized by society.
利益のためなら不道徳なことをしてもいいという考えは間違っている。
The idea that it's acceptable to do immoral things for profit is wrong.
Formed from 不 (negation prefix) + 道徳 (morality, ethics). Common collocations: 不道徳な行為 (immoral act), 不道徳な行動 (immoral behavior), and 不道徳な人 (immoral person). Compare with 非道徳 (amoral, outside the scope of morality) and 反道徳 (anti-moral, deliberately opposing morality). 不道徳 implies a failure to meet moral standards, not a rejection of morality itself.