Definition from Wiktionary, the free dictionary
bumper sticker (plural bumper stickers)
- An adhesive label or decal, usually applied to the bumper or back end of an automobile, and displaying a short political, promotional, philosophical, or humorous message.
- He has a bumper sticker on his van that reads "faster than a speeding ticket".
- Metaphorically, said of canned insight; a slogan or saying that is trite or lacks depth.