A person who is sensible enough to admit that they have no fucking clue what is going on in the universe.
Contrary to both a Theist (someone who sits in Church thinking they have shit figured out) and an Atheist (someone who sits at Starbucks thinking they have shit figured out).
Theist: "God exists." *prays*
Atheist: "God does not exist." *sips grande cappuccino*
Agnostic: "We can't know." *continues living*
A bipedal mammal that is so self-loathing that it mocks itself in every urban dictionary definition/synonym, including this one, but all-in-all is not actually that bad.
Humans are morons
Something that makes people feel like human affairs are important, despite the fact that our entire planet- nay; solar system- nay; galaxy could be wiped from existence without altering the universe in any perceptible manner.
Imagine spending your entire lifetime discussing a single electron orbiting a single hydrogen atom bonded in a single water molecule lining the digestive tract of a security guard at Kohl's with no consideration for anything else in the world. That is more or less what politics are like.