A seat in the south of central Spain (4)
I believe the answer is:
sofa
'a seat' is the definition.
(I know that Sofa is a type of seat)
'south of central spain' is the wordplay.
'south' becomes 's' (abbreviation).
'central' says to take the centre.
The centre of 'spain' is 'a'.
's'+'of'+'a'='SOFA'
'in the' is the link.
(Other definitions for sofa that I've seen before include "Chesterfield, maybe" , "Upholstered seating" , "Item of furniture" , "Lounge" , "Upholstered seat for two or more" .)