extraneous adj.

word-forming element meaning "outside; beyond the scope of; in addition to what is usual or expected," in classical Latin recorded only in extraordinarius, but more used in Medieval Latin and modern formations; it represents Latin extra (adv.) "on the outside, without, except," the old fem. ablative singular of exterus "outward, outside," comparative of ex "out of" (see ex-).

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.