A technology that concerns the control of matter on the atomic and molecular scale that goes beyond our current capabilities.

Examples:
Wesley Crusher made nano-machines work together and evolve in tng3x01 "Evolution" and things got a bit out of hand.

References:
https://en.wikipedia.org/wiki/Nanotechnology https://en.wikipedia.org/wiki/Nanotechnology_in_fiction http://www.sf-encyclopedia.com/entry/nanotechnology