Style found in composite language (4)
I believe the answer is:
elan
'style' is the definition.
(synonyms)
'in composite language' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ELAN' can be found hidden inside 'composite language'.
'found' acts as a link.
(Other definitions for elan that I've seen before include "Dash in France" , "Dash and enthusiasm." , "Energy, style and enthusiasm" , "Stylish enthusiasm" , "Dashing style" .)