Definitions of dishonorable:

• adjective:   lacking honor or integrity; deserving dishonor

  Example: "Dishonorable in thought and deed"

• adjective:   morally unacceptable

  Example: "The dishonorable conduct of trusted men"

• adjective:   deceptive or fraudulent; disposed to cheat or defraud or deceive
• adjective:   not adhering to ethical or moral principles

  Example: "Cheating is dishonorable"

• adjective:   not bringing honor and glory