A lot of US money resting on film juvenile collecting Oscar (10)
I believe the answer is:
bucketload
'a lot' is the definition.
(a bucketload is a lot of something)
'us money resting on film juvenile collecting oscar' is the wordplay.
'us money' becomes 'buck' (informal term for a US dollar).
'resting on' is a charade indicator (letters next to each other) (in a down clue, some letters go on top of others).
'film' becomes 'ET' (E.T. the Extra-Terrestrial).
'juvenile collecting oscar' becomes 'load' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'buck'+'et'+'load'='BUCKETLOAD'
'of' acts as a link.
(Other definitions for bucketload that I've seen before include "Very large amount" , "great deal" .)