■ adjective contrary to or forbidden by law.
■ noun chiefly N. Amer. an ~ immigrant.
Derivatives
~ity noun ( plural ~ities ).
~ly adverb
Usage
Illegal and unlawful have slightly different meanings. Something that is ~ is against the law, whereas an unlawful act merely contravenes the rules that apply in a particular context. Thus handball in soccer is unlawful , but not ~ . A third word with a similar meaning is illicit : this tends to encompass things that are forbidden by custom or society, as in an illicit love affair .