An aside, an act of straying from the main subject in speech or writing.
The act of straying from the main subject in speech or writing, (rhetoric) particularly for rhetorical effect.
An elongation, a deflection or deviation from a mean position or expected path.
A clue, information, argument etc. that is or is intended to be misleading, diverting attention from the real answer or issue.
A herring that is cured in smoke and brine strong enough to turn the flesh red; a type of kipper.
A red herring prospectus.