Not permitted by law: unlawful or illegal. Involves morally unacceptable behaviors. The whole meaning of illegal may be found in the English Language Learners' Dictionary. It means "not permitted by law". Illicitly means "in a manner contrary to law": illicit gains; an illicit activity. The word is used in relation to people who engage in illegal activities or possess illegal items. Or it can mean "pertaining to an illegal activity or item." For example, the possession of cocaine is a crime, so cocaine is an illicit drug. However, cocaine may be used legally as an additive for weight training supplements so this use is legal but illicit. Illegally is similar to illicitly but has a more negative connotation: illegal means "done in violation of law"; "unlawful"; "forbidden by law". For example, the possession of cocaine is a crime, so cocaine is an illegal drug. However, cocaine may be used legally as an additive for weight training supplements so this use is legal but still illegal. Thus, illicitly means "not permitted by law" and illegally means "done in violation of law".