noun. A rock-solid core of batshit-mental true believers for a cause--excuse me, for THE cause, whatever that might be--that is holy, good, pure, and of the Lord.
Real citation: "What is the barking moonbat response to Senator Clinton's sensible idea that we should work together to reduce the incidence of unintended pregnancies? She's a "phony." Abstinence or nothing is their position, no matter that it directly results in *more* unwanted pregnancies and hence *more* abortions. They don't care about that as much as they care about yelling at people not to have sex. Republican politicians are scared of alienating their loonbase by promoting better access to birth control and more affordable, more effective birth control methods. Um, here's a fact, people: if you don't get pregnant, the likelihood of your having an abortion is pretty much zero. So yes, if you believe in restricting birth control, you are not "pro-life," you are an anti-sex LOON."
(Paula Light, "The true agenda," March 2, 2005, http://paulalight.blogspot.com/2005_03_01_
Made-up citation: "I wonder how many loonwads make up the loonbase, and how many live on a moonbase?"