Antonyms of adj ethical

2 of 3 senses of ethical

Sense 2
ethical (vs. unethical) -- (conforming to accepted standards of social or professional behavior; "an ethical lawyer"; "ethical medical practice"; "an ethical problem"; "had no ethical objection to drinking"; "Ours is a world of nuclear giants and ethical infants"- Omar N. Bradley)

unethical (vs. ethical) -- (not conforming to approved standards of social or professional behavior; "unethical business practices")

Sense 3
ethical, honorable, honourable -- (adhering to ethical and moral principles; "it seems ethical and right"; "followed the only honorable course of action")

INDIRECT (VIA right) -> wrong -- (contrary to conscience or morality or law; "it is wrong for the rich to take advantage of the poor"; "cheating is wrong"; "it is wrong to lie")

Similarity of adj ethical

3 senses of ethical

Sense 1
ethical -- (of or relating to the philosophical study of ethics; "ethical codes"; "ethical theories")

Sense 2
ethical (vs. unethical) -- (conforming to accepted standards of social or professional behavior; "an ethical lawyer"; "ethical medical practice"; "an ethical problem"; "had no ethical objection to drinking"; "Ours is a world of nuclear giants and ethical infants"- Omar N. Bradley)
          Also See-> right#4

Sense 3
ethical, honorable, honourable -- (adhering to ethical and moral principles; "it seems ethical and right"; "followed the only honorable course of action")
       => right (vs. wrong) -- (in conformance with justice or law or morality; "do the right thing and confess")