Guy felt negative about clothes (4)
I believe the answer is:
gent
'guy' is the definition.
(thesaurus)
'felt negative about clothes' is the wordplay.
'clothes' says the answer is hidden in the clue (the letters clothe the hidden word).
'about' says the letters should be written in reverse.
'tneg' is hidden in the letters of 'felt negative'.
'tneg' reversed gives 'GENT'.
(Other definitions for gent that I've seen before include "Toff" , "Man of good standing (informal)" , "Chap, fellow" , "Informal and short man" , "cove" .)