A foreigner; stranger.

外国人；异乡人。

A foreign-born resident who has not been naturalized and is still a subject or citizen of a foreign country.

外侨。

Foreign; strange.

外国的；陌生的。

Living in a country not one's own.

居住他国的。

Different; contrary or opposed.

不同的；背驰的。

Belonging or pertaining to noncitizens.

非(本国)公民的。

Alien is someone who resides in a country but is not a member of it.

Alien 指定居于某一国家的居民但本身并非该国家的成员：

Foreigner is applied to a visitor or resident from another country, esp. one with a different language, culture pattern etc.

Foreigner 指自他国（尤指语言、文化不同的地）来的访客或居民。