Known in Scotland and in the Home Counties (4)
I believe the answer is:
kent
'known in scotland' is the definition.
(I've seen this before)
'and in the home counties' is the wordplay.
'and' becomes 'n' (common abbreviation for 'and').
'in the' means one lot of letters goes inside another.
'home counties' becomes 'ket' (I can't explain this - if you can you should believe this answer much more).
'n' going inside 'ket' is 'KENT'.
Can you help me to learn more?
(Other definitions for kent that I've seen before include "English architect and landscape gardener" , "known to Scots" , "County of SE England" , "County; punting pole" , "Lear's faithful Earl" .)