Dressing Ayr's latest civic dignitary (5)
I believe the answer is:
mayor
'civic dignitary' is the definition.
(I've seen this before)
'dressing ayr's latest' is the wordplay.
'dressing' becomes 'mayo' (I've seen this before).
'latest' suggests the final letters.
The last letter of 'ayr' is 'r'.
'mayo'+'r'='MAYOR'
(Other definitions for mayor that I've seen before include "Municipal leader" , "Town council head" , "Local bigwig" , "Civic official" , "Johnson, say" .)