Lot of bills (3)
I believe the answer is:
wad
'lot of bills' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for wad that I've seen before include "A thick bundle, maybe of money" , "Pad of loose material used for packing" , "Bundle of soft material or of banknotes" , "A bundle as of documents or banknotes" , "Small mass of soft material" .)