Function: noun
Date: 1873
: the number of waves per unit distance of radiant energy of a given wavelength : the reciprocal of the wavelength
Function: noun
Date: 1873
: the number of waves per unit distance of radiant energy of a given wavelength : the reciprocal of the wavelength
Merriam Webster Collegiate English Dictionary. Merriam Webster - Энциклопедический словарь английского языка. 2012