Sharp tenor dressed in fabulous net hood (2,3,3)
I believe the answer is:
on the dot
'sharp' is the definition.
(thesaurus)
'tenor dressed in fabulous net hood' is the wordplay.
'tenor' becomes 't'.
'dressed in' indicates putting letters inside.
'fabulous' indicates anagramming the letters.
'net'+'hood'='nethood'
'nethood' with letters rearranged gives 'onhedot'.
't' inserted within 'onhedot' is 'ON THE DOT'.
(Other definitions for on the dot that I've seen before include "At exactly the right time" , "Precisely punctual" , "on precise place in line?" , "Absolutely punctual" , "Prompt" .)