1. The kind of nonsense that jumps out at you when you're not expecting it. Usually from a friend's mouth.
2. Something that shouldn't be funny, but is.
3. Everything that comes out of Blue's mouth.
me: What, like alphabet soup?
me: Maybe you'll get Shakespeare.
Blue: That is some superb Ninja Nonsense right there!
"Nonsense is okay, but sensical nonsense is an extreme form of nonsense. Like Ninja Nonsense!" ~Blueberry
Suicidal sense should be a synonym for Ninja Nonsense. Sense that just kills itself.