Spot child eating fly (8)
I believe the answer is:
smidgeon
'spot child eating fly' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'spot child eating fly' is the wordplay.
'spot child' becomes 'son' (I can't justify this - if you can you should give a lot more credence to this answer).
'eating' means one lot of letters goes inside another.
'fly' becomes 'midge' (I've seen this before).
'son' placed around 'midge' is 'SMIDGEON'.
Can you help me to learn more?
(Other definitions for smidgeon that I've seen before include "A little" , "Very small part" , "Small portion" , "Small amount" , "bit" .)