Wavelength
"Wavelength can be defined as the distance between two successive crests or troughs of a wave. It is measured in the direction of the wave." (Bennett, Coleman & Co. Ltd., 2019)
Sources
"Definition of 'Wavelength'". The economic times, Bennett, Coleman & Co. Ltd. 2019.
https://economictimes.indiatimes.com/definition/wavelength.
Accessed April 1, 2019.