[dahy-uh-pey-zuh
n, -suhn] 
| 1. | a full, rich outpouring of melodious sound. |
| 2. | the compass of a voice or instrument. |
| 3. | a fixed standard of pitch. |
| 4. | 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). |
| 5. | any of several other organ stops. |
| 6. | a tuning fork. |