Worn out after book, darling? That's sweet (5,5)
I believe the answer is:
brown sugar
'sweet' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'worn out after book darling?' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'after' means one lot of letters go next to another.
'book' becomes 'b' (abbreviation for book).
'darling?' becomes 'sugar' (I've seen this in another clue).
'worn' anagrammed gives 'rown'.
'rown' put after 'b' is 'brown'.
'brown'+'sugar'='BROWN SUGAR'
'that's' is the link.
Can you help me to learn more?
(Other definitions for brown sugar that I've seen before include "Sweet thing" , "Eg, demerara" , "Demerara or muscovado, for example" , "Kind of sweetener" .)