Heralds retreat in outskirts of Paris (8)
I believe the answer is:
precedes
'heralds' is the definition.
(I've seen this before)
'retreat in outskirts of paris' is the wordplay.
'retreat' becomes 'recede' (receding is a kind of retreating).
'in' means one lot of letters goes inside another.
'outskirts of paris' becomes 'PS' (first and last letters of 'Paris').
'recede' inserted within 'ps' is 'PRECEDES'.
(Other definitions for precedes that I've seen before include "Goes before in time or order" , "has priority" , "Comes before" , "Goes in front (of)" , "Heralds" .)