According to Room, The Old Persian name for the sea was akhshaena, literally "dark," probably in reference to the sudden, dangerous storms that make the sea perilous to sailors and darken its face (or perhaps in reference to the color of the water, from the sea being deep and relatively lifeless), and the Greeks took this untranslated as Pontos Axeinos, which was interpeted as the similar-sounding Greek word axenos "inhospitable." Thus the modern English name could reflect the Old Persian one.
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.