Will eat the ice-cream, you add, inside (7)
I believe the answer is:
consume
'you add inside' is the definition.
I can't judge whether this definition defines the answer.
'will eat the ice-cream' is the wordplay.
'will' becomes 'sum' (I can't explain this - if you can you should give a lot more credence to this answer).
'eat' means one lot of letters goes inside another.
'the ice-cream' becomes 'cone' (I've seen this in other clues).
'sum' put inside 'cone' is 'CONSUME'.
Can you help me to learn more?
(Other definitions for consume that I've seen before include "Eat, drink" , "Devour" , "Exhaust" , "Use up" .)