Stiffly have argument (4)
I believe the answer is:
tiff
'argument' is the definition.
(thesaurus)
'stiffly have' is the wordplay.
'have' indicates a hidden word.
'TIFF' is hidden within 'stiffly'.
(Other definitions for tiff that I've seen before include "Slight quarrel" , "Minor argument" , "A small quarrel or spat" , "dispute" , "Row; argument" .)