Would give a great deal to hear (5)
I believe the answer is:
allot
'would' is the definition.
Although both the answer and definition are verbs in their base form, I don't see how they can define each other.
'a great deal to hear' is the wordplay.
'great deal' becomes 'lot' (both can mean a large amount).
'to' says to put letters next to each other (I've seen this in other clues).
'hear' becomes 'l' (I can't explain this - if you can you should give a lot more credence to this answer).
'lot' after 'l' is 'llot'.
'a'+'llot'='ALLOT'
'give' is the link.
Can you help me to learn more?
(Other definitions for allot that I've seen before include "Dedicate" , "Distribute, give as share" , "appropriate" , "budget" , "grant" .)