In August one has enthusiasm (5)
I believe the answer is:
gusto
'enthusiasm' is the definition.
(I know that gusto is a type of enthusiasm)
'in august one has' is the wordplay.
'in' says the answer is hidden in the clue.
'GUSTO' is hidden in the letters of 'august one has'.
(Other definitions for gusto that I've seen before include "Exuberant enjoyment" , "Zest, great enjoyment in doing" , "Relish; vigour" , "Great enthusiasm" , "exhilaration" .)