| Noun | 1. | pipe organ - wind instrument whose sound is produced by means of pipes arranged in sets supplied with air from a bellows and controlled from a large complex musical keyboardkeyboard - device consisting of a set of keys on a piano or organ or typewriter or typesetting machine or computer or the like stop - (music) a knob on an organ that is pulled to change the sound quality from the organ pipes; "the organist pulled out all the stops" wind instrument, wind - a musical instrument in which the sound is produced by an enclosed column of air that is moved by the breath | |