Should you say anything (5)
I believe the answer is:
aught
'anything' is the definition.
(thesaurus)
'should you say' is the wordplay.
'should' becomes 'ought' ('ought' can be a synonym of 'should').
'you say' shows a homophone (sound like).
'ought' sounds like 'AUGHT'.
(Other definitions for aught that I've seen before include "Nothing" , "Emphatically anything" , "Anything (Shakespearean)" , "Anything at all (archaic)" .)