Dismiss boy concealing round, large amount (8)
I believe the answer is:
shedload
'large amount' is the definition.
'dismiss boy concealing round' is the wordplay.
I cannot quite understand how this works, but
'boy' could be 'ad' and 'ad' is found in the answer.
'round' could be 'o' (round can mean a round object) and 'o' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for shedload that I've seen before include "Myriad" , "a ton" , "Lots - old heads (anag)" , "big amount" , "a lot of it" .)