Main Entry: di·a·pa·son

Pronunciation: \ˌdī-ə-ˈpā-z^ən, -s^ən\

Function: noun

Etymology: Middle English, from Latin, from Greek (hē) dia pasōn (chordōn symphōnia), literally, the concord through all the notes, from dia through + pasōn, genitive feminine plural of pas all — more at dia-, pan-

Date: circa 1501

1 a : a burst of sound <diapasons of laughter> b : the principal foundation stop in the organ extending through the complete range of the instrument c (1) : the entire compass of musical tones (2) : range, scope <registers the full diapason of her responses — Mindy Aloff>
2 a : tuning fork b : a standard of pitch