County one can possibly slog around (5)
I believe the answer is:
sligo
'county' is the definition.
(county of Ireland)
'one can possibly slog around' is the wordplay.
'one can' becomes 'i' (I can't justify this - if you can you should give a lot more credence to this answer).
'possibly' indicates anagramming the letters.
'around' means one lot of letters goes inside another.
'slog' with letters rearranged gives 'slgo'.
'i' inserted into 'slgo' is 'SLIGO'.
Can you help me to learn more?
(Other definitions for sligo that I've seen before include "part of Ireland" , "Town in north-west Ireland" , "Ir. town by Donegal bay" , "Irish county and town" , "NW Irish county" .)