Definition of illegal adjective in oxford advanced learner's dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. An illegal immigrant / alien is a person who has entered a country without government permission.

Not allowed by the rules in a game The meaning of illegal is not according to or authorized by law : Contrary to or in violation of a law : Not sanctioned by official rules (as of a game). Illegal, unlawful, illegitimate, illicit, criminal can all describe actions not in accord with law. Illegal refers most specifically to violations of statutes or, in organized athletics, codified rules: An illegal seizure of …

Illegal, unlawful, illegitimate, illicit, criminal can all describe actions not in accord with law. Illegal refers most specifically to violations of statutes or, in organized athletics, codified rules: An illegal seizure of … Forbidden by law or statute. See examples of illegal used in a sentence.