Kowabunga

[Jessica]

Great!
Not beatnik, not hippy, not swahili, but early sixties, California surfer. A corrupted version of the Hawaiian kupaianaha, which means fantastic, and any other synonym of wonderful you care to choose. The word probably entered greater American consciousness through the surfer moves of the period.
For what its worth the Teenage Mutant Ninja Turtles spoke surfer with a little valley thrown in.

[PussyCat]

This was a term used by Chief Thunderthud on the Howdy Doody show in the fifties. It was picked up by surfers in southern California in the late fifties, then skateboarders. Not Swahili, not Hawaiin, not Mutant Ninja Turtles - Howdy Doody.

[Rihanna]

The popular phrase used by the Teenage Mutant Ninja Turtles. Im guessing it means something like watch out, here I come or something of that nature. Who knows with the Ninja Turtles?

[Little_Girl]

“Kowabunga” Pronounced: Cow-a-bung-ga
“I remember back in the early 1960’s this word was used a lot, especially by beatniks and early hippies. My ninth grade english teacher told me it was Swahili for “How about that.”

[Sonia]

Go for it.

[Sarah]

When a man gently places his pinky, ring and middle fingers into a womans anus, his forefinger into her vagina and then gently rubs her clitoris with his thumb. This will often bring a woman to an orgasm very quickly. It is NOT recommended that you ask the womans permission before attemting this maneuver.

[Tina]

Word used by the Teenage Mutant Ninja Turtles meaning Turtle Power or Turtle Force.

[Tanya Shivari]

The anus of a bovine!

[Donald Trump]

While [grinding] with a female, put your hand on her head, easily pushing her head away, and lift one of your legs up.

[Becky]

wacking off with the pinky and the thumb extended in the kowabunga hand signal

[PussyCat]

While [grinding] with a female, put your hand on her head, easily pushing her head away, and lift one of your legs up.

[Guest]

@PussyCat
Congratulations, you got Thunderthud correct