nano-

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” (10-9): nanomole; nanosecond.

Also nanno-; especially before a vowel, nan-.

Origin of nano-

combining form representing Greek nânos, nánnos dwarf

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for nano-

nano-

combining form

denoting 10 –9nanosecond Symbol: n
indicating extreme smallnessnanoplankton

Word Origin for nano-

from Latin nānus dwarf, from Greek nanos

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for nano-

introduced 1947 (at 14th conference of the Union Internationale de Chimie) as a prefix for units of one thousand-millionth part, from Greek nanos "a dwarf." According to Watkins, this is originally "little old man," from nannos "uncle," masc. of nanna "aunt" (see nana). Earlier it was used as a prefix to mean "dwarf, dwarfish," and still in a non-scientific sense of "very small."

nano- in Medicine

nano-

pref.

Extremely small:nanoid.
One-billionth (10-9):nanometer.

nano- in Science

nano-

A prefix that means:
Very small or at a microscopic level, as in nanotube. In this sense, this prefix is sometimes spelled nanno-, as in nannoplankton.
One billionth, as in nanosecond, one billionth of a second.