Stupid, silly, and usually harmless actions that make reasonable people shake their heads in disbelief. Usually these are actions made by people who don't think things all the way through and/or can be described as "ding dongs".
You got a tattoo that says "$WAG" because you "thought it was funny"?! That's straight dingdongery.
Term related to an archaic device from The Before Time, The Long Long Ago. Refers to the carriage advance lever on a typewriter, so named for the characteristic *ding* made by the machine upon pushing the lever, and the *BANG!* sound made as the carriage returned to the left margin.
"To move to the next line, justslap the dingbanger."
A week after you get a new item and new wardrobe another person purchases the same item, which; could be a variation of the original item, or the exact replica. The person who is unoriginal would also be known as, a dingbonger.