'debenture' originates from Latin, specifically the word 'debentur,' where 'de-' meant 'down' and 'bentur' meant 'they owe.'

'debentur' transformed into the Medieval Latin word 'debentura,' and eventually became the modern English word 'debenture.'

Initially, it meant 'they owe,' but over time it evolved into its current meaning of 'a type of debt instrument.'