Corruption shown by a French lawyer in domed building (7)
I believe the answer is:
rotunda
'domed building' is the definition.
(I've seen this before)
'corruption shown by a french lawyer' is the wordplay.
'corruption' becomes 'rot' (I've seen this before).
'shown by' means one lot of letters go next to another.
'a french' becomes 'un' ('a' in French).
'lawyer' becomes 'da' (D.A. is an example).
'rot'+'un'+'da'='ROTUNDA'
'in' is the link.
(Other definitions for rotunda that I've seen before include "Do a turn (anag) -- circular domed building" , "Round building or hall" , "Italian Pantheon, for instance" , "Round domed building" , "domed hall" .)