Someone who is liberal or conservative when convenient because they think it makes themselves appear younger and hip. When in reality they just have a bad hip.
Someone who is perpetually on drugs and comes up to you on the street and is like, "...blah, blah, blah," for hours. All you try to do is get away but they keep yapping about bullshit that they make up. (I swear to you there is a drugtard at my door right now knocking and knocking away as I'm typing this). A lot of times they are your neighbors and you have to avoid them as much as possible because they will ask you for some stupid ass favor or make up some crisis because they have no jobs and nothing to do but be on drugs and addictive medication.
Dogtard, short for Dog Retarded, refers to dog owners that repeatedly do stupid things with their animals such as allow them to run out in the street off leash, or leave them alone in a car when its hot outside.
A joy kill that insists a good thing that everyone else is rooting for is not going to happen and/or solve a problem. A cross between a doubter and a retard.