debenture

velkasitoumus A certificate that certifies an amount of money owed to someone; a certificate of indebtedness.
puhekieltä A certificate of a loan made to the government; a government bond.
1942, Elliot Paul, The Last Time I Saw Paris, Sickle Moon 2001, p. 72:

Madame Corre, who made the important decisions after her plodding husband had spent hours on the ledger, sold the family debentures and put the money into Dutch decurities.