As fool, first among drummers, Moon cuts it (5)
I believe the answer is:
idiot
'as fool' is the definition.
'idiot' can be an answer for 'fool' (synonyms). I am unsure of the 'as' bit.
'among drummers moon cuts it' is the wordplay.
'among' is an insertion indicator (inserted letters are placed among others).
'drummers' becomes 'ido' (I can't justify this - if you can you should give a lot more credence to this answer).
'moon' becomes 'Io' (moon of Jupiter).
'cuts' means to remove the last letter (I've seen 'cutting' mean this).
'it' becomes ''t' (abbreviation. e.g. in 'tis).
'io' with its last letter taken away is 'i'.
'ido' enclosing 'i' is 'idio'.
'idio'+'t'='IDIOT'
'first' is the link.
Can you help me to learn more?
(Other definitions for idiot that I've seen before include "Sap" , "Dope" , "Dostoevsky hero" , "Foolish person" , "Charlie" .)