An unknown thingamajig. A word used by old fogies, usually in their 60s or 70s or 80s. This word imparts much aggravation on the listener, however the speaker thinks it's a clever and hip word.
Dude 1: "Yesterday in class my prof was talking about something, and he said, "So if you take this set A of dooflachees, and this set B of widgets..." and then I immediately started to doze off while mashing my teeth."
Dude 2: "Ha, that old geezer thinks that annoying old slang is cool, what a douche bag."