What does "a red herring" mean — and why is it funny?

informal

Meaning

A piece of information or a detail that is misleading and draws attention away from the real issue.

Where it comes from

A red herring is a strong-smelling smoked fish. The popular story is that it was once used to throw hunting dogs off a scent — though that tale may itself be a kind of red herring.

Why it is funny

The humor is that the phrase is sneaky about its own origin. A word for a misleading clue arrives with an origin story that historians suspect is, fittingly, misleading.

Used in a sentence

"The mysterious phone call turned out to be a red herring."