Some one who chooses not to acknowledge the obvious chemtrails in the sky are chemtards. These people are the stupidest of all primordial scum-bag primates, who for some reason or another, call themselves human. These people are usually liberal in nature, anti-constitutionalist, pro abortion, pro gay, anti gun cry baby bastards who if they live in the US aren't American at all. These people have shit for brains because they refuse to see with their own eyes the chemtrails in the skies above them, hence they're retarded, hence they are chemtards. This was the original meaning of the phrase, not the other way around.
Adrian: Hey Bob, you see all those chemtrails up their in the sky?
Bob: yeah but they're water vapour contrails.
Adrian: Oh Bob, you truly are a chemtard, dipshit moron you know that?!