bum rap

noun2

1. •
   An undeservedly unfavorable portrayal or reputation.

   • Orthopedic surgeon Robert Marx, with New York's Hospital for Special Surgery, says that findings from the current study should not give arthroscopic knee surgery a bum rap. — 2008
2. •
   (slang) A false accusation, or an injustice, especially one that leads to imprisonment.

   • . . . going over the top of the wall of the Trenton prison, where I was sent on a bum rap. — 1918