nano

IPA/næn.əʊ-/
KK[nˈæno]IPA/næn.oʊ-/

nano — prefix

1. Added before a unit of measurement to mean one thousand millionth (10⁻⁹) of that

1.prefixB2
Definition

Added before a unit of measurement to mean one thousand millionth (10⁻⁹) of that unit — for example, a nanosecond is one billionth of a second.

Example

A nanosecond equals one billionth of a second, far too fast for the human eye.

nano- + second creates nanosecond

The new processor can perform calculations in just a few nanoseconds.

Common collocations
  • nano + second
  • nano + meter
  • nano + gram
  • nano + liter
Antonyms
  • giga-

    means one billion (10⁹), the opposite scale direction

Grammar Patterns

nano- + [unit of measurement]

Usage Note

This is an SI (International System of Units) prefix. It attaches directly to measurement words such as meter, second, gram, and liter without a hyphen in standard spelling. Although nano- is historically a combining form from Greek, it now functions as a productive SI prefix for any new measurement term.

Common Mistakes

A nanosecond is one billionth of a microsecond.
A nanosecond is one billionth of a second, and a microsecond is one millionth of a second.
nano- (10⁻⁹) and micro- (10⁻⁶) differ by a factor of 1,000.

2. Added before nouns in science and technology to refer to things that are built,

2.prefixB2
Definition

Added before nouns in science and technology to refer to things that are built, measured, or operated at the scale of individual atoms and molecules.

Example

Nanotechnology allows engineers to build tiny machines that work at the molecular level.

nano- + technology: engineering at molecular scale

Nanoparticles in this sunscreen block UV rays without leaving a white layer on the skin.

Common collocations
  • nano + technology
  • nano + particle
  • nano + material
  • nano + scale
  • nano + robot

Grammar Patterns

nano- + [noun]

Usage Note

This sense is most common in compound words related to nanotechnology, materials science, and medicine. It implies working at a scale of 1-100 nanometers.

3. Used to form established scientific compound nouns where nano- attaches to a non

3.prefixC1
Definition

Used to form established scientific compound nouns where nano- attaches to a non-unit noun to describe something of nanometer-scale or billionth-scale size — for example, nanoplankton are tiny organisms that pass through normal filters.

Example

Nanoplankton are so small that they pass through most standard filtering nets.

nano- + plankton: billionth-scale organisms

The geologist identified nanofossils in the sediment that date back millions of years.

Common collocations
  • nano + plankton
  • nano + fossil
  • nano + structure
  • nano + bubble

Grammar Patterns

nano- + [noun (non-unit)]

Usage Note

This reflects the older combining-form tradition from Greek, where nano- was attached to scientific nouns rather than SI units. Unlike the SI prefix (sense 1), this pattern is not productive for new terms — it occurs in already-established vocabulary such as nanoplankton, nanofossil, and nanostructure.

Word family

  • nanotechnology
    nounB2
  • nanometer
    nounB2
  • nanosecond
    nounB2
  • nanoscale
    adjectiveC1
  • nanoparticle
    nounC1
  • nanomaterial
    nounC1
  • nanorobot
    nounC1
  • nanotech
    nounC1
  • nanoplankton
    nounC1
  • nanofossil
    nounC1
  • nanostructure
    nounC1
  • nanobubble
    nounC1

Synonym discussion

Sense: prefix/1

All three are SI prefixes that attach to measurement units to indicate a fraction of the base unit. Micro- (10⁻⁶) is one millionth and is widely understood from everyday contexts like micrometer and microsecond. Nano- (10⁻⁹) is one billionth — a thousand times smaller than micro- — and is the key prefix for modern electronics and molecular science. Pico- (10⁻¹²) and femto- (10⁻¹⁵) are used mainly in specialized physics and chemistry (picosecond laser pulses, femtosecond spectroscopy). The scale difference matters enormously: a microsecond is the blink of a camera flash, but a nanosecond is the time light travels about 30 centimeters. Knowing which prefix applies helps you interpret measurements in scientific reading correctly.

micro-pico-femto-

Common collocations

Nouns

  • nano + second
  • nano + meter
  • nano + gram
  • nano + liter
  • nano + technology
  • nano + particle
  • nano + material
  • nano + scale
  • nano + robot
  • nano + structure
  • nano + fossil
  • nano + plankton
  • nano + bubble

Phrases

  • at the nanoscale
  • nano-level precision

Etymology

GreekFrenchEnglish

From the Greek word νᾶνος (nános), meaning 'dwarf' or 'tiny person'. The term entered French and then English scientific usage in the 20th century when the International System of Units (SI) adopted 'nano-' as the official prefix for one billionth (10⁻⁹) in 1960.