County Kerry's neighbour cut large grassy area back (8)
I believe the answer is:
cornwall
'county' is the definition.
'cut large grassy area back' is the wordplay.
'cut' becomes 'cor' (I can't justify this - if you can you should give a lot more credence to this answer).
'large' becomes 'L' (eg in clothes sizes).
'grassy area' becomes 'lawn' (I've seen this before).
'back' is a reversal indicator.
'l'+'lawn'='llawn'
'llawn' backwards is 'nwall'.
'cor'+'nwall'='CORNWALL'
'kerry's neighbour' acts as a 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 cornwall that I've seen before include "County in SW England" , "County touching only one other" , "Southwestern English county" , "Duchy" , "hilly county" .)