Spicy pepper: Rod has urge to tuck in (7)
I believe the answer is:
cayenne
'spicy pepper' is the definition.
(I know that cayenne is a type of spicy pepper)
'rod has urge to tuck in' is the wordplay.
'rod has' becomes 'cane' (I can't explain this - if you can you should give a lot more credence to this answer).
'urge' becomes 'yen' (yen can mean a craving for something).
'to tuck in' means one lot of letters goes inside another.
'cane' placed around 'yen' is 'CAYENNE'.
Can you help me to learn more?
(Other definitions for cayenne that I've seen before include "Hot red powdered pepper" , "Variety of pepper" , "Dried chilli powder" , "South American capital" , "Pungent red pepper" .)