Ceremonial procedure by enthusiast, nothing held back (8)
I believe the answer is:
ritenuto
'held back' is the definition.
The answer and definition are different parts of speech. However, past participle verbs and adjectives occasionally define each other.
'ceremonial procedure by enthusiast nothing' is the wordplay.
'ceremonial procedure' becomes 'rite' (I've seen this in another clue).
'by' is a charade indicator (letters next to each other).
'enthusiast' becomes 'nut' (nut can mean an enthusiast or fan).
'nothing' becomes 'O' (looks like zero - 0).
'rite'+'nut'+'o'='RITENUTO'
Can you help me to learn more?
(Other definitions for ritenuto that I've seen before include "coming to a sudden slowdown" , "Immediately reducing in speed (music)" , "slowing immediately" .)