Empty or insincere talk; claptrap.
Talk that is empty, insincere, or merely for effect; humbug.
(Washington circa 1828) Any bombastic political posturing or an oratorical display not accompanied by conviction; speechmaking designed for show or public applause.
Origin of bunkum
In 1820, Felix Walker, who represented Buncombe County, North Carolina, in the U.S. House of Representatives, rose to address the question of admitting Missouri as a free or slave state. This was his first attempt to speak on this subject after nearly a month of solid debate and right before the vote was to be called. Allegedly, to the exasperation of his colleagues, Walker insisted on delivering a long and wearisome "speech for Buncombe." He was shouted down by his colleagues. His persistent effort made "buncombe" (later respelled "bunkum") a synonym for meaningless political claptrap and later for any kind of nonsense. Although he was unable to make the speech in front of Congress it was still published in a Washington newspaper.