The distance? If that is the question then the answer is "wave length".
Wave Length
The distance from one wave crest to the next one is called a wavelength.
Wavelength
wavelengthWAVELENGTH
The distance between one crest of a wave and the next is called its wavelength.
That's called a 'wavelength'.
That distance is called the wavelength.
in order to find the wavelength, you measure the distance from one crest to the next.
That's the 'wavelength'.
wave-length, designated by lamda
Wave length
That is the same as the wavelength, or the definition of a wavelength.