Diapason

dī-a-pā′zon, n. a whole octave: a harmony: a full volume of various sounds in concord: correct pitch: the two foundation-stops of an organ ( open and stopped diapason )—( Spens. ) Dī′apase . [Gr. dia , through, and pasōn , gen. pl. of pas , all—part of the Gr. phrase, dia pasōn chordōn symphōnia , concord through all the notes.]