A native of Ayrshire, say, somewhere in Berkshire (5)
I believe the answer is:
ascot
'in berkshire' is the definition.
(I've seen this before)
'a native' is the wordplay.
'native' becomes 'scot' (I have seen 'Native of Glasgow' mean 'scot' so perhaps 'native' could also mean 'scot').
'a'+'scot'='ASCOT'
'of ayrshire say somewhere' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for ascot that I've seen before include "Berkshire town, famous for horse racing" , "English horse racing venue on coast" , "Fungus affecting wood" , "Posh racecourse" , "Tie round the neck" .)