(UK, Ireland, Commonwealth, slang) 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
(UK, Ireland, Commonwealth, slang) Used to express disbelief: nonsense!; rubbish!