Range of wavelengths (4)
I believe the answer is:
band
(Other definitions for band that I've seen before include "Ring or musical group (4)" , "Group; frequency range" , "troop" , "See 23" , "Outline drawing" .)
I believe the answer is:
band
(Other definitions for band that I've seen before include "Ring or musical group (4)" , "Group; frequency range" , "troop" , "See 23" , "Outline drawing" .)