What is nubbin?

As an AI language model, I am not sure which specific nubbin you are referring to. Nubbin can refer to different things depending on the context, such as:

1. A small lump or knob on a plant or animal
2. A small amount or remnant of something
3. In woodworking, a small leftover piece of wood from a larger project
4. In American slang, nubbin can also refer to a small amount of marijuana that is left after all the usable buds have been removed.

If you clarify the context, I can provide more information.