A natural instrument of action or operation, or by which some process is carried on. Thus the arteries and veins of animal bodies are organs of circulation; the lungs are organs of respiration; the nerves are organs of perception and sensation; the muscles are organs of motion; the ears are organs of hearing; the tongue is the organ of speech.

The instrument or means of conveyance or communication. A secretary of state is the organ of communication between the government and a foreign power.

The largest and most harmonious of wind instruments of music, consisting of pipes which are filled with wind, and stops touched by the fingers. It is blown by a bellows.