Perform in French before a court (5)
I believe the answer is:
enact
'perform' is the definition.
(I've seen this before)
'in french before a court' is the wordplay.
'in french' becomes 'en' (French word for 'in').
'before' is a charade indicator (letters next to each other).
'court' becomes 'ct' (abbreviation used in road names).
'en'+'a'+'ct'='ENACT'
(Other definitions for enact that I've seen before include "Official order" , "get into law" , "Decree" , "Bring in" , "Play one's part" .)