from The American Heritage® Dictionary of the English Language, 4th Edition
- Extremely small: nannoplankton.
- One billionth (10-9): nanosecond.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10−9. Symbol: n
- Derived from the nanotechnology industry
from the GNU version of the Collaborative International Dictionary of English
- A prefix meaning one-billionth.
- Very small; submicroscopic; -- used to designate sizes smaller than those that would be referred to as
Greek nānos, nannos, little old man, dwarf, from nannās, uncle.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin nanus ("dwarf"), from Ancient Greek νᾶνος (nanos). (Wiktionary)