a swinging or sliding barrier that will close the entrance to a room or building or vehicle; "he knocked on the door"; "he slammed the door as he left"
a room that is entered via a door; "his office is the third door down the hall on the left"
a structure where people live or work (usually ordered along a street or road); "the office next door"; "they live two doors up the street from us"
anything providing a means of access (or escape); "we closed the door to Haitian immigrants"; "education is the door to success"
a high-pitched woodwind instrument; a slender tube closed at one end with finger holes on one end and an opening near the closed end across which the breath is blown
a groove or furrow in cloth etc (particularly a shallow concave groove on the shaft of a column)