Scotch on the rocks? No - dark, sweet stuff (9)
I believe the answer is:
liquorice
'scotch' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'on the rocks? no dark sweet stuff' is the wordplay.
'on' says to put letters next to each other.
'the rocks?' becomes 'ice' (as in a drink on the rocks).
'no dark sweet stuff' becomes 'liquor' (I can't explain this - if you can you should believe this answer much more).
'ice' put after 'liquor' is 'LIQUORICE'.
Can you help me to learn more?
(Other definitions for liquorice that I've seen before include "Confectionary flavoured with root extract" , "Pontefract cake ingredient" , "Plant that's root is used in confectionery" , "Sweet" , "Flavour for allsorts" .)