dishonourable

lacking honor or integrity; deserving dishonor

• “dishonorable in thought and deed”
• “a dishonorable discharge”

not adhering to ethical or moral principles

• “base and unpatriotic motives”
• “a base, degrading way of life”
• “cheating is dishonorable”
• “they considered colonialism immoral”
• “unethical practices in handling public funds”

morally unacceptable

• “the dishonorable conduct of trusted men”