[ nan-oh, ney-noh ]
/ ˈnæn oʊ, ˈneɪ noʊ /
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Informal. nanotechnology.
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Origin of nano

By shortening

Other definitions for nano (2 of 2)


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. 2022


What does nano- mean?

Nano– is a combining form used like a prefix meaning “very small, minute.” In names of units of measure, it means “one billionth.” It is often used in scientific and technical terms.

Nano– comes from Greek nânos or nánnos, meaning “dwarf.”

What are variants of nano-?

In some rare instances, nano– is spelled with a double -n-, becoming nanno-, as in nannofossil.

When combined with words or word elements that begin with a vowel, nano– becomes nan-, as in nanoid. Want to know more? Read our Words That Use nan article.

Examples of nano-

An example of a word you may have encountered that features nano– is nanosecond, “one billionth of a second.”

The form nano– generally means “very small, minute,” but because a second is a unit of measure (of time), here nano– means “one billionth.” Nanosecond literally means “one billionth of a second.”

What are some words that use the combining form nano-?

What are some other forms that nano– may be commonly confused with?

Break it down!

A gram is a unit of weight or mass. With this in mind, what is a nanogram?

How to use nano in a sentence

British Dictionary definitions for 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

Medical definitions for nano


Extremely small:nanoid.
One-billionth (10-9):nanometer.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for nano


A prefix meaning one billionth.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.