A revolution printed so much paper money its own name became an insult

To fund the war effort after 1775, the Continental Congress printed roughly $200 million in paper 'Continentals', with no coordinated tax base or bond sales to back them and British operatives counterfeiting them at scale. By 1780 the notes traded at around 1/40th of face value, and by mid-1781 they had stopped circulating altogether. The collapse was so total that 'not worth a continental' became a lasting American phrase for something utterly worthless.

— Wikipedia contributors, Continental currency — Issued by the Continental Congress, 1775–1781