Most showy tousled style (7)
I believe the answer is:
loudest
'most showy' is the definition.
'tousled style' is the wordplay.
'style' indicates anagramming the letters (style can mean to shape or design).
'tousled' with letters rearranged gives 'LOUDEST'.
(Other definitions for loudest that I've seen before include "Most deafening" , "Noisiest or gaudiest" , "Most flashy" , "Most noisy" , "Making the most noise" .)