Stranger, foreigner, alien, outlander, outsider, immigrant, émigré can all designate a person who comes into a community from the outside and is not recognized as a member of that community.
This is the primary denotation of some of the words, but the secondary sense of the others, especially the last three. Stranger and foreigner may both apply to one who comes from another country or sometimes from another section as a resident or visitor.
They have somewhat different implications, however, stranger stressing the person’s unfamiliarity with the language and customs and foreigner the fact that he speaks a different language, follows different customs, or bears allegiance to another government.
Alien emphasizes allegiance to another sovereign or government and is often opposed to citizen ; thus, one may be called a foreigner after naturalization, but not with accuracy an alien . In extended use alien can imply either exclusion from full privileges of or inability to identify oneself with a group.
Outlander , in its general sense, is preferred to foreigner only for a literary or rhetorical reason or because it carries the implications of outlandish .
Outsider usually implies nonmembership in a group, clique, or caste largely because of essential differences in origin, interests, backgrounds, customs, and manners.
Immigrant and émigré are often used of foreigners who are residents and no longer aliens.
Immigrant usually is applied to a foreigner who has come voluntarily, typically in search of a better means of earning a living or a more satisfying way of life; émigré implies that the foreigner is a fugitive or refugee from his native land or, in a weaker sense, that he has left his abiding place rather from dissatisfaction than from strong hope for a better future.