Dictator's stone castle, somewhere in France (9)
I believe the answer is:
roquefort
'france' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'dictator's stone castle somewhere' is the wordplay.
'dictator's' shows a homophone (sound like) (as somebody dictating would pronounce the word).
'stone' becomes 'rock' (synonyms).
'castle somewhere' becomes 'fort' (fort is a type of castle. I am not sure about the 'somewhere' bit.).
'rock' sounds like 'roque'.
'roque'+'fort'='ROQUEFORT'
'in' is the link.
Can you help me to learn more?
(Other definitions for roquefort that I've seen before include "Cheese made from ewes' and goats' milk" , "French blue cheese" , "French cheese - for torque (anag)" , "Soft blue ewe's cheese" , "French blue-veined cheese" .)