A mild moan about monarch included fauna (6,7)
I believe the answer is:
animal kingdom
'fauna' is the definition.
(thesaurus)
'a mild moan about monarch included' is the wordplay.
I cannot quite see how this works, but
'a' could be 'an' and 'an' is present in the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is found within the answer.
'monarch' could be 'king' (king is a kind of monarch) and 'king' is present in the answer.
an anagram of 'mild' is 'imld' which is within the remaining letters.
The remaining letters 'om' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for animal kingdom that I've seen before include "Creatures collectively" , "Moving organisms in general" , "beasts in general" , "beastly lot" .)