Cowabunga

[Justin Bieber]

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.

[Tanya Shivari]

60s SoCal surfer slang popularized by artist Matt Goenings 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 Thinderthuds greeting and his peanut gallerys response on the old time (1950s) childrens TV show Howdy Dowdy, an eponym for its cowboy manikin. Back then, on old corny Westerns, an Amerindians 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.

[Britney]

A expression used to express happiness

[Justin Bieber]

a cool word used mostly by surfers to greet each other, say they are having a good time or just happy.

[Becky]

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.

[Rihanna]

A funny word for Endearment.

[Rihanna]

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.

[Sarah]

Positive, Good, Great, in an aspect greater than cool.
mostly used by headbangers, metalheads, skaters, surfers, and ninja turtles.

[Sonia]

a singular word expressing appreciation of an amusing physical action.

I took to saying it to my bulldog and pitbull in appreciation of their leaping on the kitchen table or doing something otherwise physically dramatic. Such as falling off the couch. I believe I picked it up from Homer Simpson.

Itd be quite cool if the American Indian history is accurate.

[Tina]

When you pull a girls [bloody tampon] out and [swing it] like a [nunchuk] and hit her in the face with it.

[Michiko]

its [just a word] u [yell] out...kinda like [woohoo]

[Becky]

A [greeting] used by only the most intelligent. Often said or used while ([orgasming]) or (shooting the [goo])

[Rihanna]

Quirky [Sallys] definition is fine, but the word originated from [surfer] slang in the early [sixties].

[Donald Trump]

when you are [smoking pot], and you dont realize your high until [5 or 10] [minutes] later!

[Julene]

Used to express delight or satisfaction.