A slang term for one's testicles, balls.
Not to be confused with Kahunas that has a different meaning, though sounding identical.
While the spelling is different, (Kahoonas vs. Kahunas) the sound of the word is identical, yet it does have a different meanings associated with each spelling.
Kahoonas also refers to a male's nerve, to their courage.
To refer to one having 'big Kahoonas' meaning the person had a lot of nerve, exhibited a great deal of courage in a specific situation.