Quirky Sally's definition is fine, but the word originated from surfer slang in the early sixties.
Cowabunga! Look at her ride that wave.
(exclamation): Originating as a greeting by Chief Thunderthud (the only Indian ever to have a moustache) to the Peanut Gallery
on the 50's television program "The Howdy Doody Show", the term was later adopted by surfers in the 60's.
Chief Thunderthud: Cowabunga, peanuts!
The Peanut Gallery: Cowabunga!
Surfer: Cowabunga, dude!
An exclamation of rejoice from the early 1990s. Usually uttered by teenagers wearing neon colors. Brought to popularity by the ever-so-famous Teenage Mutant Ninja Turtles.
Leonardo: The pizza just got here!
Michaelangelo: COWABUNGA dude!
60s SoCal surfer slang popularized by artist Matt Goening's animated skateboarding cartoon character Bart Simpson, son of Homer "Doh!" Simpson, on the still running ― 20+ years ― "The Simpsons" TV show.
Of course, surfers picked word up ― as Vermont Ferret wrote ― from Chief Thinderthud's greeting and his peanut gallery's response on the old time (1950s) children's TV show "Howdy Dowdy," an eponym for its cowboy manikin. Back then, on old corny Westerns, an Amerindian's greeting was stereotypically, "How!" to be rejoined with a "How!" So How morphed into Cow and an "abunga" was added for silly kid ― or those with Peter Pan syndrome ― fun.
Cowabunga is a slang term of surprise. It is incorrectly credited as becoming part of the lexicon when it appeared in the Ninja Turtle movies in the early 1990s. In fact this word dates back to 1964 when it was first heard in the movie "Pajama Party".
a cool word used mostly by surfers to greet each other, say they are having a good time or just happy.
Kelly Slater- "Cowabunga!"
Laird Hamilton- "Totally, dude, this party is awesome!"
A funny word for Endearment.
My dear Cowabunga
Someone who throws a cow, in a cow throwing contest.
Derived form the sport of cow throwing. The participant in the event.
Bung as in to throw, makes the entrant a 'Bunga'.
The winner of the world cow throwing championships, is crowned world champion Cowabunga.