Dictionary.com
definitions

roorback

or roor·bach

[roo r-bak]
noun
  1. a false and more or less damaging report circulated for political effect, usually about a candidate seeking an office.

Origin of roorback

1844, Americanism; after a fictitious Baron von Roorback, in whose travelogue occurred an account of an incident damaging to the character of James K. Polk
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for roorback

roorback

noun
  1. US a false or distorted report or account, used to obtain political advantage

Word Origin for roorback

C19: after Baron von Roorback, invented author of an imaginary Tour through the Western and Southern States (1844), which contained a passage defaming James K. Polk
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012