Cuban perhaps getting ground into endless misery (8)
I believe the answer is:
islander
'cuban perhaps' is the definition.
(Cuba is an island)
'ground into endless misery' is the wordplay.
'ground' becomes 'land' (synonyms).
'into' means one lot of letters goes inside another.
'endless' indicates the central letters.
The centre of 'misery' is 'iser'.
'land' inserted inside 'iser' is 'ISLANDER'.
'getting' is the link.
(Other definitions for islander that I've seen before include "Isolated dweller" , "One living surrounded by water" , "a Corsican, perhaps" , "Inhabitant of Fiji, for example" , "Manxman, maybe," .)