diffusion

American  

[dih-fyoo-zhuhn] / dɪˈfju ʒən /

noun

• diffusions
  plural

1. the act of diffusing or state of being diffused.

   During the gradual, unorchestrated diffusion of ideas from science into the surrounding culture, crucial information can sometimes be lost.

2. excessive wordiness of speech or writing; long-windedness.

3. Physics.

   1. Also called migration.  an intermingling of molecules, ions, etc., resulting from random thermal agitation, as in the dispersion of a vapor in air.

   2. a reflection or refraction of light or other electromagnetic radiation from an irregular surface, or an erratic dispersion through a surface; scattering.

4. Movies. a soft-focus effect resulting from placing a gelatin or silk plate in front of a studio light or a camera lens, or through the use of diffusion filters.

5. Meteorology. the spreading of atmospheric constituents or properties by turbulent motion as well as molecular motion of the air.

6. Also called cultural diffusion.  Anthropology, Sociology. the transmission of elements or features of one culture to another.

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diffusion British  

/ dɪˈfjuːʒən /

noun

1. the act or process of diffusing or being diffused; dispersion

2. verbosity

3. physics

   1. the random thermal motion of atoms, molecules, clusters of atoms, etc, in gases, liquids, and some solids

   2. the transfer of atoms or molecules by their random motion from one part of a medium to another

4. physics the transmission or reflection of electromagnetic radiation, esp light, in which the radiation is scattered in many directions and not directly reflected or refracted; scattering

5. Also called: diffusivity.  physics the degree to which the directions of propagation of reverberant sound waves differ from point to point in an enclosure

6. anthropol the transmission of social institutions, skills, and myths from one culture to another

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diffusion Scientific  

/ dĭ-fyo̅o̅′zhən /

1. The movement of atoms or molecules from an area of higher concentration to an area of lower concentration. Atoms and small molecules can move across a cell membrane by diffusion.

2. Compare osmosis

3. The reflection or refraction of radiation such as light or sound by an irregular surface, tending to scatter it in many directions.

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diffusion Cultural  

1. The spreading of atoms or molecules of one substance through those of another, especially into liquids or gas es.

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Other Word Forms

Derived Forms

• interdiffusion
  noun
• nondiffusion
  noun
• overdiffusion
  noun
• rediffusion
  noun
• self-diffusion
  noun

Inflected Forms

Nouns

• diffusions
  plural

Etymology

Origin of diffusion

First recorded in 1325–75; Middle English, from Latin diffūsiōn-, stem of diffūsiō “a spreading out”; equivalent to diffuse + -ion

Explanation

Diffusion is the act of dispersing something, spreading it out from a central point. When an idea catches on, that's a type of diffusion. When you spray air freshener and the scent spreads from a tight space to fill a larger one, that's diffusion. In science, diffusion is a physical process of atoms or molecules moving apart within a gas or liquid. You can also use the word diffusion to describe the spreading of information. Ever notice how a trendy word or band will suddenly be everywhere, even though nobody heard of it last week? That's diffusion. This word means something similar to dispersal and dissemination.

Example Sentences

See Examples For:

diffusion diffusions

"The result is fewer firms growing to global size and slower diffusion of new technologies across the economy."

From Barron's ● Aug. 19, 2026

This architecture also supports molecular diffusion and traps incoming photons, helping the light-driven reactions proceed more effectively.

From Science Daily ● Aug. 6, 2026

Grain boundary diffusion involves applying tiny quantities of the most expensive and elusive rare earths, known as heavy rare earths, to a magnet to make it heat-resistant without sacrificing magnetic strength.

From The Wall Street Journal ● Jun. 29, 2026

"How to respond to the rapid development and diffusion of generative AI is the biggest 360-degree challenge for today’s news leaders and policymakers," Egan wrote.

From Barron's ● Jun. 15, 2026

These examples, at first so bizarre to us, illustrate well the roles of geography and of diffusion in the history of technology.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

"If countries are found to be significantly and persistently abusing red notices and diffusions, then they should be suspended from the system for a period of time," says Keith.

From BBC ● Jan. 25, 2026

The clear sculpture that results is meant to afford the viewer a purely sensual delight in the infinite variety of light, its perpetual diffractions, spontaneous diffusions and prismatic permutations that can go on forever.

From Time Magazine Archive

As a member of the British trio Cream, he transformed simple blues lines into brilliant horizontal diffusions of sound.

From Time Magazine Archive

The author exhibits the result of thoughtful study in his expressed views upon the mooted questions of racial origins and diffusions.

From Eighth Annual Report of the Bureau of Ethnology to the Secretary of the Smithsonian Institution, 1886-1887, Government Printing Office, Washington, 1891 by John Wesley Powell

The inmates we found pious, sensible, and excellent persons, who had devoted many years among their heathen neighbors in philanthropic diffusions of the Gospel.

From Los Gringos Or, An Inside View of Mexico and California, with Wanderings in Peru, Chili, and Polynesia by H. A. (Henry Augustus) Wise

Related Words

• dispersal
• dispersion
• dissemination
• dissipation