French engineer, in some reports, is quite a sight (6)
I believe the answer is:
eyeful
'quite a sight' is the definition.
(something eye-catching)
'french engineer in some reports' is the wordplay.
'french engineer' becomes 'Eiffel' (Gustave Eiffel).
'in some reports' shows a homophone (sound like) (report can mean to speak).
'eiffel' is a homophone of 'EYEFUL'.
'is' acts as a link.
(Other definitions for eyeful that I've seen before include "Interesting sight - beautiful woman" , "beauty!" , "One who is well worth looking at" , "Gorgeous sight" , "Something worth looking at" .)