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defocus

American  
[dee-foh-kuhs] / diˈfoʊ kəs /

verb (used with object)

defocused, defocusing, defocussed, defocussing
  1. to cause loss of focus of.

    The slightest movement will defocus the microscope.

  2. to interrupt or disturb (concentration, attention, etc.).

  3. to disturb the concentration or awareness of (someone).


verb (used without object)

defocused, defocusing, defocussed, defocussing
  1. to lose or go out of focus.

  2. to lose concentration or awareness; become distracted.

noun

  • defocuses
    plural
  1. the result of defocusing, as a blurred photographic image.

Other Word Forms

Noun Inflected Forms


Etymology

Origin of defocus

First recorded in 1930–35; de- + focus


Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

I was disappointed with the mic quality and background defocus button as well.

From The Verge ● Oct. 6, 2021

Do you prep, defocus to clear your head for the next day’s possibilities, socialise, stay isolated and meditative?

From The Guardian ● Jun. 12, 2020

To express boredom, an anthropomorphic device may defocus its gaze, direct its gaze in a downward fashion, tap its foot, and/or close its eyes.

From Time ● May 22, 2015

For the analysis of the TcdA1 pore complex, 605 images were taken at a magnification of ×124.472 and a defocus range of 0.4–2.9 µm.

From Nature ● Apr. 4, 2014

Didn't you ever stop to think that a few air molecules could defocus the stream?

From Teething Ring by Dick Francis

Reaching that goal may require another improvement: using a tightly focused electron beam rather than the defocused beam currently needed to produce sufficient contrast without the laser phase plate.

From Science Daily ● Oct. 22, 2026

It suggests that some mental processes linked to ADHD, including defocused attention, may also support creative thinking when they are directed in productive ways.

From Science Daily ● Sep. 3, 2026

However, light passing through the ring itself is defocused slightly meaning that the peripheral retina gets a slightly blurred image.

From BBC ● Jul. 10, 2025

Martindale and his group interpreted alpha power as a marker of decreased cortical arousal and defocused attention and suggested that creative people were allowing more information into their conscious awareness during creative work.

From Scientific American ● Apr. 14, 2011

In fact, the cyclotron had been working perfectly well with beams far more defocused by imperfections in the magnetic field—those bothersome irregularities combated by shimming—than they would be by the relativistic effects that Bethe posited.

From "Big Science" by Michael Hiltzik

The KU researcher said the combination of a defocusing magnetospheric plasma and a focusing gravity create in-phase and out-of-phase interference bands of radio-wave intensity that appear as the Crab Pulsar's zebra stripes.

From Science Daily ● Mar. 28, 2026

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