- a full, rich outpouring of melodious sound.
- the compass of a voice or instrument.
- a fixed standard of pitch.
- either of two principal timbres or stops of a pipe organ, one of full, majestic tone (open diapason ) and the other of strong, flutelike tone (stopped diapason ).
- any of several other organ stops.
- a tuning fork.
- either of two stops (open and stopped diapason) usually found throughout the compass of a pipe organ that give it its characteristic tone colour
- the compass of an instrument or voice
- (chiefly in French usage)
- a standard pitch used for tuning, esp the now largely obsolete one of A above middle C = 435 hertz, known as diapason normal (French (djapazɔ̃ nɔrmal)
- a tuning fork or pitch pipe
- (in classical Greece) an octave
