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.
In complete confusion and unable to comprehend anything. A complete death of ones IQ and Common Sense. (Typically happens when over flowed with emotion)
Did you see after (insert name) got they got their first kiss they went through dingdongdeath