Nanotechnology is the science of making or working with things that are so small that they can only be seen using a powerful microscope.
nanotechnology in British English
(ˌnænəʊtɛkˈnɒlədʒɪ) or nanotech (ˈnænəʊˌtɛk)
noun
a branch of technology dealing with the manufacture of objects with dimensions of less than 100 nanometres and the manipulation of individual molecules and atoms
nanotechnology in American English
(ˌnænoʊtɛkˈnɑlədʒi)
noun
a hypothetical method or process of creating microminiature equipment by manipulating atoms and molecules as if they were parts of a machine