diffusion

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noun dif·fu·sion \ di-ˈfyü-zhən \

Definition of diffusion

1 :the state of being spread out or transmitted especially by contact :the action of diffusing

the diffusion of knowledge

2 :prolixity, diffuseness

3 a chemistry :the process whereby particles of liquids, gases, or solids intermingle as the result of their spontaneous movement caused by thermal (see ¹thermal 1b) agitation and in dissolved substances move from a region of higher to one of lower concentration

b physics

(1) :reflection of light by a rough reflecting surface

(2) :transmission of light through a translucent material :scattering

4 :the spread of cultural elements from one area or group of people to others by contact

5 photography :the softening of sharp outlines in an image

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diffusional

play \-ˈfyü-zhə-nᵊl\ adjective

See diffusion defined for kids

Examples of diffusion in a Sentence

the author's tendency toward diffusion makes the novel a tedious read

Recent Examples of diffusion from the Web

Inca embalming of their dead was attributed instead to natural mummification by the elements or to the diffusion of Egyptian knowledge.

— christopher heaney, The Atlantic, "The Racism Behind Alien Mummy Hoaxes," 1 Aug. 2017
Military acquisition authorities need to think harder about second- and third-order diffusion effects (like armed Islamic State drones in Mosul).

— chicagotribune.com, "America needs a new 'dreadnought strategy'," 28 July 2017
And this is not just among students or graduates, which suggests that there could be some kind of knock-on effect associated with universities through the diffusion of ideas into their surrounding areas.

— the tylt, AL.com, "Are colleges harming America?," 18 July 2017
That led to widespread condemnation the launch of a field of inquiry called diffusion of responsibility by Princeton’s John Darley and Bibb Latane.

— jeffrey sonnenfeld, Fortune, "What a Fourth of July Beach Rescue Says About America’s True Heroes," 15 July 2017
Choose from a variety of dry-air diffusion capsules—seaside, espresso, even croissant.

— deanna cioppa, Marie Claire, "These 4 Must-Have Gadgets Will Make You Sleep *So* Much Better," 20 June 2017
Barrett, one the most charming and compelling designers on the schedule, is meeting Vogue Runway to discuss this long planned diffusion collection dedicated to working out.

— luke leitch, Vogue, "Putting the "Fit" Into Fitness: Neil Barrett launches BLACKBARRETT," 12 June 2017
Another left-wing node of conspiratorial diffusion can be found at The Palmer Report, a once relatively obscure pro-Hillary blog that has built a large following with its wildly speculative theories about Trump.

— colin dickey, New Republic, "Karl Rove panicked on live television," 8 June 2017
A top official at the French presidency said the new unit will notably determine strategies to fight against radicalization on the internet and diffusion online of instructions on how to carry out an attack.

— Washington Post, "French president Macron creates new counterterrorism unit," 7 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'diffusion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of diffusion

see ²diffuse

NEW! Time Traveler

First Known Use: 15th century

See Words from the same year

diffusion Synonyms

Other Physics Terms

amplitude, centrifugal, centripetal, convection, gradient, hysteresis, kinetic, lase, quantum

DIFFUSION Defined for Kids

diffusion

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noun dif·fu·sion \ di-ˈfyü-zhən \

Definition of diffusion for Students

1 :the act of spreading or allowing to spread freely

2 :the mixing of particles of liquids or gases so that they move from a region of high concentration to one of lower concentration

Medical Dictionary

diffusion

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noun dif·fu·sion \ dif-ˈyü-zhən \

medical Definition of diffusion

1 :the process whereby particles of liquids, gases, or solids intermingle as the result of their spontaneous movement caused by thermal agitation and in dissolved substances move from a region of higher to one of lower concentration

2 a :reflection of light by a rough reflecting surface

b :transmission of light through a translucent material

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