noun
: a tuning standard of 435 to 439 vibrations per second for A above middle C adopted in Britain at the end of the 19th century to replace the old philharmonic pitch
noun
: a tuning standard of 435 to 439 vibrations per second for A above middle C adopted in Britain at the end of the 19th century to replace the old philharmonic pitch
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012