Something that is self-evident. A condition of obviousness.
Person 1: "I named my newly captured pet toad Moot for what I hope are obvious reasons."
Person 2: "I see no obviousity."
Obviousities are nouns that are blatant.
Example 1: "Did you see that ninja? Yes? Exactly. He's an obviousity, and needs to be fired."
Example 2: "Spare me the statistical obviousities and give me the details!"