strange: [13] The etymological notion underlying strange is of being ‘beyond the usual bounds or boundaries’. This evolved into ‘foreign’ (which survives in the closely related French étrange) and ‘odd’. The word came via Old French estrange from Latin extrāneus ‘foreign, strange’ (source of English extraneous [17]), an adjective based on extrā ‘outward, outside’. Stranger [14] goes back to *extrāneārius, a Vulgar Latin derivative of extrāneus; and another derivative, extrāneāre ‘alienate’, produced English estrange [15]. => estrange, extraneous[strange etymology, strange origin, 英语词源]