Squash one who's mad about the spread? (9)
I believe the answer is:
butternut
'squash' is the definition.
(butternut squash is a kind of squash)
'one who's mad about the spread?' is the wordplay.
'one who's mad' becomes 'nut' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'about' says to put letters next to each other.
'the spread?' becomes 'butter' (butter is a spread).
'nut' put after 'butter' is 'BUTTERNUT'.
Can you help me to learn more?
(Other definitions for butternut that I've seen before include "species of tree" , "Variety of pumpkin" , "sort of a squash" , "Wood" .)