Meaning of nano-

nano-

Pronunciation: [key]
  1. a combining form with the meaning “very small, minute,” used in the formation of compound words (nanoplankton); in the names of units of measure it has the specific sense “one billionth” (10): nanomole; nanosecond.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.