Refers to the "evidentiary" accumulation of old dusty "spider-lace" over the access-opening to some area or device, thus proving to observers that you have indeed not been messing around in said locale, just as you'd stated you hadn't.
When the well-servicing guys came to replace my submersible water-pump and removed the well-pipe's outer cap, there was a thick layer of obviously-many-years-old cobweboration layered over the end of the pipe, showing the guys beyond any doubt that this was the first time it had been uncovered since they themselves had installed it well over a decade earlier. I gigglingly said, "You see? Long live spider's webs! This proves conclusively that I haven't had my cotton-pickin' hands down there, and so the pump's malfunctioning couldn't possibly have had anything to do with meddling on my part!"
by QuacksO May 08, 2019