Harry is upset by early start in part of Scotland (8)
I believe the answer is:
ayrshire
'part of scotland' is the definition.
(I've seen this before)
'harry is upset by early start' is the wordplay.
'upset by' indicates anagramming the letters.
'start' suggests taking the first letters.
The initial letter of 'early' is 'e'.
'harry'+'is'='harryis'
'harryis' with letters rearranged gives 'ayrshir'.
'ayrshir'+'e'='AYRSHIRE'
'in' is the link.
(Other definitions for ayrshire that I've seen before include "part of Scotland" , "Historic county of Scotland" , "Eg bull" , "Breed of dairy cattle has rye hairs" , "Burns's county" .)