1. An instrument in which musical tones that are generated by electronically driven reeds are processed, amplified, and passed through a set of loud speakers.
2. A musical instrument that uses electronic circuits to produce music similar to that of a pipe organ.
3. An electrophonic instrument played by means of a keyboard in which sounds are produced and amplified by any of various electronic or electrical methods.
4. The electronic counterpart of the pipe organ where all tones and tone variations; such as, vibrato, tremolo, etc., are produced by electronic circuits instead of by pipes.