Where did the phrase "Jump the Shark" originate?

"Jumping the shark" is an idiom used to describe a moment when something that was once widely popular, but has since grown less popular, makes a misguided attempt at generating publicity that instead only serves to highlight its irrelevance. This is especially applicable to television series or other entertainment outlets. The phrase derives from a 1977 episode of the sitcom "Happy Days" (1974–1984), in which the character Fonzie jumps over a shark while on water-skis. This gimmick strayed absurdly outside the original storyline of the sitcom.

The idiom "jumping the shark" is pejorative, most commonly used in reference to unsuccessful gimmicks for promoting something. It is similar to being past its peak, but it more specifically suggests an unwillingness to acknowledge the fact. Originally, the phrase was used to describe an episode of a television comedy with a gimmick or unlikely occurrence desperately attempting to keep viewers' interest. Moments labeled as "jumping the shark" are considered indications that writers have exhausted their focus, that the show has strayed irretrievably from an older and better formula, or that the series as a whole is declining in quality.