The term "improper purpose" refers to an intention or motive that is not in line with accepted standards of conduct, morality, or law. It suggests a lack of proper justification or reason for doing something and can be used to describe behavior that is considered wrongful, unethical, or malicious. In legal contexts, the phrase may refer to an intentional act committed with an improper purpose, which could negate any valid defense or mitigating circumstance.