Fat it is said of the land (6)
I believe the answer is:
greece
'the land' is the definition.
(Greece is an example)
'fat it is said' is the wordplay.
'fat' becomes 'grease' (animal fat for cooking).
'it is said' shows a homophone (sound like).
'grease' sounds like 'GREECE'.
'of' acts as a link.
(Other definitions for greece that I've seen before include "Modern-day classical Hellas" , "The country sounds slippery" , "European nation" , ""The cradle of civilisation"" , "Country of Sophocles and Plato" .)