noun
reserve fund; emergency fund
Money set aside for unexpected expenses or future needs. Used in personal finance, business, and government contexts.
会社は不況に備えて予備金を積み立てている。
The company is building up a reserve fund in case of recession.
急な出費のために予備金を用意しておくといい。
It's good to have an emergency fund for sudden expenses.
準備金 is a similar term often used in accounting or legal contexts for reserves set aside for specific purposes.
Compound of 予備 (yobi, 'reserve, spare') and 金 (kin, 'money').