Dine with nothing but oxtail, say (4)
I believe the answer is:
soup
'oxtail say' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'dine with nothing' is the wordplay.
'dine' becomes 'sup' (synonyms).
'with' is an insertion indicator.
'nothing' becomes 'O' (looks like zero - 0).
'sup' enclosing 'o' is 'SOUP'.
'but' is the link.
Can you help me to learn more?
(Other definitions for soup that I've seen before include "Liquid - course" , "See 19" , "Bisque, for example" , "Eg, mulligatawny" , "Eskimo people" .)