sinking fund
noun [ C ]
ukus FINANCE
money that a company pays into an account so that it can pay investors, lenders, etc. the money it owes them:
By paying off a portion of its debt each year with the sinking fund, the company will face a much smaller final bill.
PROPERTY UK
an account into which all owners of apartments in a building make regular payments for future repairs to the building:
Make sure that the block in which you are buying a flat has a healthy sinking fund.