Contrary to or prohibited by moral standards or religious precepts; immoral, unethical; wicked, sinful.

Lacking sound or honourable principles; immoral.

Not consistent with, or not conforming to, moral law or requirement; opposed to or violating morality; morally evil or impure; unprincipled, vicious…

Not moralized; deprived of or lacking any moral sense or quality.

Not moral; having no moral sense or standards; not concerned with morality. Cf. amoral, adj.

Having no moral or morals.

= unethical, adj.

(un-, prefix1 affix 1.)

colloquial. Of questionable morality or ethics; troublesome or difficult to deal with.