English county of French and German origin (5)
I believe the answer is:
devon
'english county' is the definition.
(I've seen this before)
'of french and german origin' is the wordplay.
'of french' becomes 'de' ('of' in French).
'and' means one lot of letters go next to another.
'german origin' becomes 'von' (I can't explain this - if you can you should believe this answer much more).
'de'+'von'='DEVON'
Can you help me to learn more?
(Other definitions for devon that I've seen before include "Clotted-cream county" , "part of England?" , "English county" , "Raleigh's county" , "County in southwestern England" .)