A door to a church; a church door.

The frame into which a door is fitted.

(UK, rail transport) Applied to an older kind of passenger train with heavy doors, opened from the inside by reaching out of the window to the handle on the outside.

A doggie door.

A cat flap.

plural of door pump

weatherstrip to seal the door when closed.

A hydraulic device attached to a door in its one end and to the doorframe in the other, performing one or more of the following functions: a) dampening the movements of the door, b) making sure that the door closes properly, and c) assisting in opening it.

plural of door-mat (alternative form of doormats).

plural of door-bell (alternative form of doorbells).