Fruit stack in Irish county (8)
I believe the answer is:
limerick
'irish county' is the definition.
(I've seen this before)
'fruit stack' is the wordplay.
'fruit' becomes 'lime' (lime is a kind of fruit).
'stack' becomes 'rick' (ricking is a kind of stacking).
'lime'+'rick'='LIMERICK'
'in' acts as a link.
(Other definitions for limerick that I've seen before include "Humorous poem of 5 lines, and Irish county" , "[EDWARD LEAR] work" , "Humorous poem from the Treaty City?" , "Five-lined poem" , "Verse form - Irish city" .)