Money raised by word of mouth (5)
I believe the answer is:
bread
'money' is the definition.
(slang term for money)
'raised by word of mouth' is the wordplay.
'raised by word of' becomes 'b' (I can't justify this - if you can you should give a lot more credence to this answer).
'mouth' becomes 'read' (reading is a kind of mouthing).
'b'+'read'='BREAD'
Can you help me to learn more?
(Other definitions for bread that I've seen before include "Dosh (slang)" , "Baked food; money" , "brass" , "It's made with 23" , "Eg, loaf or roll" .)