Definition of Foreigner
In old English law, this term, when used with reference to a particular city, designated any person who was not an inhabitant of that city. According to later usage, it denotes a person who is not a citizen or subject of the state or country of which mention is made, or any one owing allegiance to a foreign state or sovereign.
Person belonging to or under citizenship of another country.
That's the definition of Foreigner in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.