English spelling altered 17c., perhaps by influence of reign, sovereign. Sense of "alien to one's nature, not connected with, extraneous" attested late 14c. Meaning "pertaining to another country" (as in foreign policy) is from 1610s. Replaced native fremd. Related: Foreignness. Old English had ælþeodig, ælþeodisc "foreign," a compound of æl- "foreign" + þeod "people."
In ordinary use chiefly applied to those who speak a foreign language as their native tongue; thus in England the term is not commonly understood to include Americans. [OED]
In American English from 1620s through mid-19c., however, it was used of a person from a different colony or state. Earlier as a noun in English was simple foreign (early 14c.), probably from Old French, which used the adjective as a noun meaning "foreigner;" also "outskirts; the outside world; latrine, privy." Spelling furriner, representing pronunciation, is from 1832, originally in Irish dialect pieces but by 1840s picked up by American dialect writers (Thomas Chandler Haliburton).
"suburb," late 15c. (early 15c. fabour), from Old French forsbourc, faubourg (12c.) "suburbs, outskirts," literally "that which is outside the town," from fors "outside" (from Latin foris; see foreign) + bourc "town" (a word of Frankish origin cognate with English borough). Altered in French by folk-etymology to faux bourg "false town" (suburbs were seen as inauthentic).
c. 1300, "strange, foreign," from Old French alien "strange, foreign;" as a noun, "an alien, stranger, foreigner," from Latin alienus "of or belonging to another, not one's own, foreign, strange," also, as a noun, "a stranger, foreigner," adjective from alius (adv.) "another, other, different," from PIE root *al- (1) "beyond."
Meaning "residing in a country not of one's birth" is from mid-15c. Sense of "wholly different in nature" is from 1670s. Meaning "not of this Earth" first recorded 1920. An alien priory (mid 15c.) is one owing obedience to a religious jurisdiction in a foreign country.
late 13c., straunge, "from elsewhere, foreign, unknown, unfamiliar, not belonging to the place where found," from Old French estrange "foreign, alien, unusual, unfamiliar, curious; distant; inhospitable; estranged, separated" (Anglo-French estraunge, strange, straunge; Modern French étrange), from Latin extraneus "foreign, external, from without" (source also of Italian strano "strange, foreign," Spanish extraño), from extra "outside of" (see extra-). In early use also strounge. The surname Lestrange is attested from late 12c. Sense of "queer, surprising" is attested from c. 1300, also "aloof, reserved, distant; estranged." In nuclear physics, from 1956.