Loud operation for the dude (3)
I believe the answer is:
fop
'the dude' is the definition.
(synonyms)
'loud operation' is the wordplay.
'loud' becomes 'f' (short for forte - 'loud' in music).
'operation' becomes 'op'.
'f'+'op'='FOP'
'for' is the link.
(Other definitions for fop that I've seen before include "A dandy, overdressed man" , "fashionable type" , "A dandy like Beau Brummel" , "One affected" , "Gallant" .)