The adverb of unethical: doing something in a way that breaks the standards of right conduct, especially professional ones. It attaches to how a person or company acted — they behaved unethically, the money was obtained unethically, he acted unethically but within the law. In real use it clusters around a few verbs: behave, act, obtain, source, treat. You meet it in news reports, workplace complaints, court cases and company policies rather than in conversation. Because it is an accusation, speakers often soften it or hedge it — "arguably unethically", "what many saw as acting unethically" — since, as with unethical, people can genuinely disagree about where the line sits.