diffusion

American  

[dih-fyoo-zhuhn] / dɪˈfyu ʒən /

noun

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

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

Etymology

Origin of diffusion

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

Example Sentences

Previously, scientists believed actin mainly reached this region by random diffusion.

From Science Daily • Apr. 1, 2026

The second set focused on chest X-rays, with half real and half created using RoentGen, an open-source generative AI diffusion model developed by Stanford Medicine researchers.

From Science Daily • Mar. 26, 2026

“Multiple industry players over time, particularly Nvidia, have argued that smuggling or diffusion of AI technologies to China were tall tales,” Burnham said.

From MarketWatch • Mar. 21, 2026

“We need to work on the assumption that AI diffusion is here to stay,” Nageswaran said.

From The Wall Street Journal • Mar. 11, 2026

Let us now summarize how variations in these three factors—time of onset of food production, barriers to diffusion, and human population size—led straightforwardly to the observed intercontinental differences in the development of technology.

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

Related Words

• dispersal
• dispersion
• dissemination
• dissipation