Deposit small sum of money in crumpled tens (8)
I believe the answer is:
sediment
'deposit' is the definition.
('sediment' can be a synonym of 'deposit')
'small sum of money in crumpled tens' is the wordplay.
'small sum of money' becomes 'dime'.
'in' indicates putting letters inside.
'crumpled' indicates an anagram.
'tens' anagrammed gives 'sent'.
'dime' placed within 'sent' is 'SEDIMENT'.
(Other definitions for sediment that I've seen before include "Deposit at the bottom of a liquid" , "Remains" , "Material settling out in a liquid" , "Lees" , "Silt" .)