French city trip curtailed by unpleasant person (8)
I believe the answer is:
toulouse
'french city' is the definition.
(I've seen this before)
'trip curtailed by unpleasant person' is the wordplay.
'trip' becomes 'tour' (I've seen this before).
'curtailed' means to remove the last letter.
'by' is a charade indicator (letters next to each other).
'unpleasant person' becomes 'louse' (louse is a kind of unpleasant person**).
'tour' with its last letter taken off is 'tou'.
'tou'+'louse'='TOULOUSE'
(Other definitions for toulouse that I've seen before include "Southern French city" , "City in SW France" , "Lautrec's French town" , "City in southern France" , "French city near Bordeaux" .)