Although the U.S. National Nanotechnology Initiative’s previous definition of nanotechnology was confusing, at least they were trying to make it more relevant than the usual “anything 1-100 nm” nanotech definition used by so many.
Sadly, they’ve given up and are now using this: “Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications.”
For the earlier definition, see the FDA website, which — as I write this — is still using the old NSF/NNI definition
But the FDA will probably update at some point, so when that happens, see the Internet Archive record from March 2005. Sigh. This is what happens when you set up a distributive coalition. —Christine