Parisian district needs rainstorm desperately? (14)
I believe the answer is:
arrondissement
'parisian district' is the definition.
(type of administrative district in Paris)
'needs rainstorm desperately?' is the wordplay.
'desperately?' indicates an anagram (I've seen 'desperately' mean this).
'needs'+'rainstorm'='needsrainstorm'
'needsrainstorm' anagrammed gives 'ARRONDISSEMENT'.
(Other definitions for arrondissement that I've seen before include "Zone de Paris" , "Paris area" .)