Fruit beside a haystack in Munster (8)
I believe the answer is:
limerick
'in munster' is the definition.
(I know that Munster contains administrative territorial entity Limerick)
'fruit beside a haystack' is the wordplay.
'fruit' becomes 'lime' (lime is a kind of fruit).
'beside' means one lot of letters go next to another (I've seen this in other clues).
'a haystack' becomes 'rick' (synonyms).
'lime'+'rick'='LIMERICK'
(Other definitions for limerick that I've seen before include "Humorous short poem" , "City of humorous verse" , "Irish county - five-line poem" , "Verse form - Irish city" , "Five-lined poem" .)