Average, though dim when turned up (3)
I believe the answer is:
mid
'average' is the definition.
(thesaurus)
'dim when turned up' is the wordplay.
'dim' can be anagrammed to 'MID'.
Though, I am not sure how the anagram is indicated.
'though' is the link.
Can you help me to learn more?
(Other definitions for mid that I've seen before include "Of the central part" , "Dim sort of prefix" , "Denote the centre point" , "Prefix meaning centre" .)