DEBENTURE. A certificate given, in pursuance of law, by the collector of a port of entry, for a certain sum, due by the United States, payable at a time therein mentioned, to an importer for drawhack of duties on merchandise imported and exported by him, provided the duties arising on the importation of the said merchandise shall have been discharged prior to the time aforesaid. Vide Act of Congress of March 2, 1799, s. 80; Encyclop6die, h. t.; Dane's Ab. Index, h. t.