also: たんすよきん
noun
mattress money; cash kept at home
Refers to money saved privately at home, often in a drawer or under a mattress, instead of being deposited in a bank. Commonly used in economic contexts discussing unproductive savings.
日本ではタンス預金が数十兆円あると言われている。
It is said that there are tens of trillions of yen in mattress money in Japan.
祖母は銀
My grandmother doesn't trust banks and keeps her savings at home.