Leaving England's capital for somewhere in Somerset (5)
I believe the answer is:
frome
'somewhere in somerset' is the definition.
The definition suggests a singular noun which matches the answer.
'leaving england's capital' is the wordplay.
'leaving england' becomes 'f' (I can't justify this - if you can you should believe this answer much more).
'capital' becomes 'Rome' (capital of Italy).
'f'+'rome'='FROME'
'for' is the link.
Can you help me to learn more?
(Other definitions for frome that I've seen before include "Somerset town" , "West Country town" .)