Typically it's "feature pitch", or an overall scale of the various features involved in producing a transistor like width and height. You can see more on the b

Typically it's "feature pitch", or an overall scale of the various features involved in producing a transistor like width and height. You can see more on the breakdown on pages like this: https://en.wikipedia.org/wiki/10_nanometer https://en.wikipedia.org/wiki/10_nanometer It's more a marketing term since no particular component is exactly 10nm, but it's based on a composite of the features involved.