Illegal alien

What is Illegal alien?

Illegal alien definition and meaning on Dictionary terms:
noun Often Disparaging and Offensive.
a foreigner who has entered or resides in a country unlawfully or without the country’s authorization.
a foreigner who enters the U.S. without an entry or immigrant visa, especially a person who crosses the border by avoiding inspection or who overstays the period of time allowed as a visitor, tourist, or businessperson.Compare resident alien.