WordNet sense 1 (not adhering to ethical or moral principles):

base, dishonorable, unethical, dishonourable

WordNet sense 2 (contrary to conscience or morality or law):

wrong

WordNet sense 3 (unrestrained by convention or morality):

dissipated, dissolute, fast, profligate

WordNet sense 4 (characterized by wickedness or immorality):

bad

WordNet sense 5 (morally bad or wrong):

evil

WordNet sense 6 (marked by immorality; deviating from what is considered right or proper or good):

depraved, perverse, perverted, reprobate

WordNet sense 7 (lacking in integrity):

corrupt