Poles bring in money over time, a very small amount (7)
I believe the answer is:
neutron
'amount' is the definition.
(I have seen 'tiny amount' mean 'neutron' so perhaps 'amount' could also mean 'neutron')
'poles bring in money over time a very small' is the wordplay.
I cannot quite see how this works, but
'over' could be 'on' (physically on top of) and 'on' is located in the answer.
'time' could be 't' (abbreviation) and 't' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for neutron that I've seen before include "Subatomic particle with no electric charge" , "Uncharged atomic particle" , "Charged particle" , "tiny amount" , "Turn one (anag) - kind of bomb" .)