noun

1. Senseless talk or writing; nonsense; rubbish.

   “1993, J. Neville Turner, The One-Day Game – Cricket or Codswallop?, in 2001, David John Headon, The Best Ever Australian Sports Writing: A 200 Year Collection.”

interjection

1. Used to express disbelief: nonsense!; rubbish!

Synonyms: hogswallop