Tacit support behind the Sun's outrage (6)
I believe the answer is:
unsaid
'tacit' is the definition.
(I've seen this in another clue)
'support behind the sun's outrage' is the wordplay.
I cannot quite see how this works, but
'support' could be 'aid' (to aid is to help or support) and 'aid' is found in the answer.
an anagram of 'sun' is 'uns' which is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for unsaid that I've seen before include "withdrawn" , "Not made explicit" , "not stated?" , "not pronounced" , "omitted from speech" .)