Butler spoils veal temperature (5)
I believe the answer is:
valet
'butler' is the definition.
(thesaurus)
'spoils veal temperature' is the wordplay.
'spoils' indicates an anagram.
'temperature' becomes 't' (abbreviation).
'veal' is an anagram of 'vale'.
'vale'+'t'='VALET'
(Other definitions for valet that I've seen before include "dresser" , "Gentleman's gentleman" , "Personal serving man" , "Gentleman's attendant" , "Personal male assistant" .)