Defeats in slick style (5)
I believe the answer is:
licks
'defeats' is the definition.
(I've seen this in another clue)
'in slick style' is the wordplay.
'in' indicates the answer is hidden within the clue.
'LICKS' is hidden in the letters of 'slick style'.
(Other definitions for licks that I've seen before include "Laps" , "Thrashes" , "Beats (slang)" , "Music" , "musical flourishes" .)