Similar to
the definition of funny, but used when the one writing it either wants to show that the funny thing is either not funny, but clearly trying to be. It can also be the opposite when something is not trying to be funny yet is, or is dumb
in the way it's funny.
It's either a perfect sarcastic response or an acknowledgement of caveman brain humor.
The word funne is pronounced differently than funny. Pronounce it like a caveman would and
you're pretty much there.