מסתבר שכן (אל תטרחו לחפש תשובה- היא בתגובה)
 
העיוות של המילה כנראה התחיל בגרמניה. בכל אופן הנה הסיפור:
From Middle English dore, dor, from Old English duru (“door”), dor (“gate”), from Proto-Germanic *durz, from Proto-Indo-European *dʰwer- (“doorway, door, gate”). Cognates include Saterland Frisian Doore (“door”), West Frisian doar (“door”), Dutch deur (“door”), Low German Door, Döör (“door”), German Tür (“door”), Tor (“gate”), Danish dør (“door”), Icelandic dyr (“door”), Latin foris, Greek θύρα (thúra), Albanian derë pl. dyer, Kurdish derge (der), derî, Persian در (dar), Russian дверь (dverʹ), Hindustani द्वार (dvār) / دوار (dvār), Armenian դուռ (duṙ), Irish doras, Lithuanian durys.
 
מקור:
https://en.wiktionary.org/wiki/door#English