Twelve hang out in gap between peaks? (10)
I believe the answer is:
wavelength
'gap between peaks?' is the definition.
I can't tell whether this defines the answer.
'twelve hang out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'twelve'+'hang'='twelvehang'
'twelvehang' anagrammed gives 'WAVELENGTH'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for wavelength that I've seen before include "Identification of radio station" , "surfers may maximise use of?" , "Property of radio signal, light, etc" .)