1.
foreigner; non-Japanese person
A person from another country, especially as seen from a Japanese perspective. More casual and sometimes considered less polite than the formal equivalent.
2.
outsider; stranger to a group
Someone who does not belong to a particular group or community.
外 (outside) + 人 (person). Shortened form of 外国人. Very commonly used in everyday speech but can carry a distancing or othering nuance that some find insensitive. In formal writing and official contexts, 外国人 is always preferred.
Usage
While not inherently a slur, 外人 is perceived by many non-Japanese residents as exclusionary. The word tends to draw a sharp line between Japanese and non-Japanese and can feel reductive. Awareness of this nuance has grown, and many Japanese speakers now prefer 外国人 or 外国の方 in polite contexts.