Foreign means belonging to another country. A foreign language, foreign travel, foreign currency.
In official use it names whole institutions: the Foreign Office, foreign policy, a foreign correspondent. There is a second, figurative sense meaning completely unfamiliar or unnatural: that kind of thinking is foreign to her. And in medicine, a foreign body is something that should not be there — a splinter, a swallowed coin. Note that foreigner, applied to a person, can sound cold in modern English, and the usual alternatives are visitor, overseas or the person's actual nationality.
1adjectiveforeignBelonging to a country that is not your own.
“She speaks three foreign languages.”
synonyms: overseas, international
2adjectivecompletelyCompletely unfamiliar or unnatural to somebody.
“Working in an office was entirely foreign to him.”
3adjectivecomingComing from outside a body or a system.
“There was a foreign body in the wound.”
Too few real examples of this word to estimate which sense is commonest.
foreign is a relation to another country.
Latin foras meant outside or out of doors, and Vulgar Latin foranus meant an outsider. The g in foreign was added in English by mistaken analogy with sovereign, which also has a g it never earned. Two words are misspelled together for company.
Middle English
foreyn
English, today
foreign
Built from
From Middle English foreyn. From Middle English foreyn,forein, from Old French forain, from Vulgar Latin forānus (“outsider, outlander”), from Latin forās (“outside, outdoors”) or forīs (“outside, outdoors”). Displaced native elþēodiġ and now-dialectal fremd, from fremde.
Etymology from Wiktionary, CC BY-SA