a long rambling joke whose humor derives from its pointlessness

a long meandering story which is only funny because the punch line is so flat you wondered why the tale was told at all

an extremely long and involved joe with aweak or completely nonexistent punchline

an extremely long and involved joke with a weak or completely nonexistent punchline

a somewhat intricate, sometimes lengthy story that serves as a setup to a groaner of a bad punch line

a story, usually very long, that is built around a single premise, usually a punch line or a pun

In its original sense, a shaggy-dog story is an extremely long-winded tale featuring extensive narration of typically irrelevant incidents, usually resulting in a pointless or absurd punchline. These stories are also known as yarns, coming from the long tradition of campfire yarns.

Shaggy Dog Story was a charity programme for Children in Need, put together by the BBC in 1999 as a sequel to the previous year's Future Generations video (featuring chilcren's programmes), and the great success of 1997's Perfect Day charity single.