It contains some money, and it's possible to get the rest from Wall Street (6)
I believe the answer is:
wallet
'it contains some money and it's possible to get' is the definition.
The definition suggests a singular noun which matches the answer.
'rest from wall street' is the wordplay.
'from' suggests deleting specific letters.
'wall'+'street'='wallstreet'
'wallstreet' with 'rest' removed is 'WALLET'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for wallet that I've seen before include "Small case for paper money" , "Billfold (US)" , "Folding case for money" , "Small flat money case" , "Pocket-size case" .)