guncotton guhn ko tuhn n a nitric acid ester; used in lacquers and explosives Usage(s) A roll of ordinary ticker-tape, turned into guncotton, was fed between two copper rolls into the cylinder and exploded electrically. Huge quantities of guncotton were made from cotton received a bale at a time. Since then he has had one du Pont job after another: black powder, sporting powder, guncotton. Synonym(s) cellulose nitrate nitrocellulose nitrocotton