Foreign
Middle English foren, forein, from Old French forein, forain, based on Latin foras, foris ‘outside’, from fores ‘door’. The current spelling arose in the 16th century, by association with sovereign.
wiktionary
From Middle English foreyn, forein, from Old French forain, from Vulgar Latin *forānus(“outsider, outlander”), from Latin forās(“outside, outdoors”), also spelled forīs(“outside, outdoors”).
Displaced native Middle English elendish, ellendish(“foreign”) (from Old English elelendisc, compare Old English ellende(“foreign”), elland(“foreign land”)), Middle English eltheodi, eltheodish(“foreign”) (from Old English elþēodiġ, elþēodisc(“foreign”)), and non-native Middle English peregrin(“foreign”) (from Old French peregrin).
The silent -g- added perhaps by analogy with reign (compare also sovereign which was similarly altered). No relation with German fremd, Dutch vreemd.
etymonline
foreign (adj.)
c. 1300, ferren, foran, foreyne, in reference to places, "outside the boundaries of a country;" of persons, "born in another country," from Old French forain "strange, foreign; outer, external, outdoor; remote, out-of-the-way" (12c.), from Medieval Latin foraneus "on the outside, exterior," from Latin foris (adv.) "outside," literally "out of doors," related to foris "a door," from PIE *dhwor-ans-, suffixed form of root *dhwer- "door, doorway."
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."
