Leave after endless mistake in county (5)
I believe the answer is:
sligo
This could be a double definition.
'leave after endless mistake' is the first definition.
The definition suggests a singular noun which matches the answer.
'county' is the second definition.
(county of Ireland)
'in' is the link.
Can you help me to learn more?
(Other definitions for sligo that I've seen before include "part of Ireland" , "County of northwest Ireland" , "one of twenty-six" , "area by the sea" , "Irish county and town" .)