To give hundreds back is silly (4)
I believe the answer is:
daft
'silly' is the definition.
(I've seen this in another clue)
'to give hundreds back' is the wordplay.
'to give' means one lot of letters go next to another.
'hundreds' becomes 'd' (I've seen this in other clues).
'back' becomes 'aft' (associated in meaning).
'd'+'aft' is 'DAFT'.
'is' is the link.
(Other definitions for daft that I've seen before include "Scatty" , "Informally crazy as a brush" , "Bats!" , "like a brush?" , "Potty" .)