noun

1. a movable structure for opening or closing an entrance, as to a building or room, or giving access to a closet, cupboard, etc.: most doors turn on hinges, slide in grooves, or revolve on an axis
2. the room or building to which a particular door belongs two doors down the hall
3. any opening with a door in it; doorway
4. any way to go in or out; passage; access

Etymology: ME dure, dor < OE duru fem. (orig., pair of doors), dor neut., akin to Ger tür, door, tor, gate < IE base *dhwer-, *dhwor-, door > L fores (pl. of foris), two-leaved door, Gr thyra, door (in pl., double door)