No, Woodworker's Wotsits is not a delicate euphemism for something nasty... Just the bits, bobs and puzzlements that seem to inevitably stumble across the woodworker's path. I'm sure we've all scratched our heads trying to identify a particular timber, or a particular tool (or more likely, part of a tool.) Normally you at least get a vague idea straight away; animal, vegetable or mineral? Or rather; wood or tool?
I received this in the post the other day, and I can safely say I didn't have a clue until I opened it. No idea whether it's a common thing or not, so I'll leave it as a hanging "wotsit" until tomorrow, so you can be clever and/or guess. It's about 3" wide, if that helps.