外人 refers to someone who is not part of a particular group — family, organization, or community. It can mean 'stranger' (someone you don't know), 'outsider' (someone not in the inner circle), or 'foreigner' (someone from another country). The exact equivalent in English depends on the context, so you cannot always translate it as the same English word. In a company, 外人 means an outsider who doesn't belong; in a family setting, it suggests someone unrelated; in a national context, it means a foreigner.