Spare food for Jack Sprat (4)
I believe the answer is:
lean
'spare' is the definition.
(similar in meaning)
'food for jack sprat' is the wordplay.
I cannot quite see how this works, but
'food' could be 'e' (E is an example) and 'e' is located in the answer.
The remaining letters 'lan' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for lean that I've seen before include "Spare - list" , "Spare - incline" , "Without excess flesh" , "Containing little fat" , "With no fat; slope" .)