BASSES: The largest pipes in the organ.  The bottom notes of a given stop.

ACTION:  An action may be mechanical, pneumatic, or electrical (or some combination of these, such as electro-pneumatic action). An organ contains two actions, or systems of moving parts. When a key is depressed, the key action admits wind into a pipe. The stop action allows the organist to control which ranks are engaged.    An electrical connection which, when charged, it magnetizes a piece of metal. This circuit is involved in the mechanism which opens the valves to allow pipes to speak

BLOWER: In organs of the twentieth century, a rotary fan for producing organ wind, usually driven by an electric motor. The wind supplied is stored in one or more regulators to maintain a constant pressure in the windchests until the action allows it to flow into the pipes

BODY: The upper part of a flue pipe, measured upward from the mouth to the end of the pipe.  A pipe body may be either open, closed or partially closed.

BOXES:  Usually refers to a swell box.  See Swell shutters.

BOOT: The lower part of a reed pipe, containing the sound-producing mechanism: shallot and tongue.