2/6/17 The Difference between Unlawful, Illegal, Illicit, and Criminal
These appear in order of increasing stigma.
An unlawful act is one not approved by law, but not necessarily against the law, either. It could be a civil wrong, or an offense that no one would consider particularly blameworthy, such as overparking.
An illegal act is a violation of law, but even this term can apply to civil offenses.
Illicit carries a strong connotation of immorality, and criminal denotes punishable wrongdoing.