foreigner, foreign, alien

Definition:

The term "foreigner" refers to a person living in a country that is not his own. Another name for a foreigner is an "alien."

In the Old Testament, this term especially refers to anyone who came from a different people group than the people he was living among.
A foreigner is also a person whose language and culture is different from your own.
For example, when Naomi and her family moved to Moab, they were foreigners there. When Naomi and her daughter-in-law Ruth later moved to Israel, Ruth was called a "foreigner" there because she was not originally from Israel.
The apostle Paul told the Ephesians that before they knew Christ, they were "foreigners" to God's covenant.
Sometimes "foreigner" is translated as "stranger," but it should not only refer to someone who is unfamiliar or unknown.