Expedition to the French metropolis goes around a river (8)
I believe the answer is:
alacrity
'expedition' is the definition.
(I've seen this before)
'to the french metropolis goes around a river' is the wordplay.
'to the french' becomes 'a la' ('to the' in French).
'metropolis' becomes 'city' (a metropolis is a large city).
'goes around' means one lot of letters goes inside another.
'a river' becomes 'r' (abbreviation for river).
'city' placed around 'r' is 'crity'.
'ala'+'crity'='ALACRITY'
(Other definitions for alacrity that I've seen before include "Showing brisk readiness" , "prompt response" , "Promptness, eagerness" , "Lively enthusiasm" , "Expedition" .)