noun. An uncanny, tingly, weirdo-detecting mechanism in the brain, possibly buried somewhere near the corpus callosum.
Related terms: gaydar, straightdar, bi-dar, loserdar, jailbaitdar, moron-dar, sexual-geniusdar, "someone is staring at my ass"-dar.
Real citation: "Why do weirdo's have an affinity for me? Do I have weirdo-dar? Or do weirdos just have excellent taste?"
(Dec. 12, 2003, Diary Quotes, http://www.diarytown.com/diaryquotes/archives/001891.html)
Made-up citation: "Unfortunately for me, my weirdo-dar is on the fritz, but I do have fully functioning pretty-dar and cake-dar."