Land in Paris (Le Bourget?) (4)
I believe the answer is:
'land' is the definition.
(isle is a kind of land)
'in paris le bourget?' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ISLE' is hidden in the letters of 'paris le bourget'.
(Other definitions for isle that I've seen before include "I shall hear" , "Land surrounded entirely by water" , "Man conceivably" , "Lies about small land mass." , "Said of Sheppey, Dogs, Wight or Man?" .)