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).

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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

• defocuses
  plural

Etymology

Origin of defocus

First recorded in 1930–35; de- + focus

Example Sentences

See Examples For:

defocus defocused defocusing

I took this camera out for a day in Brooklyn to put its in-camera stabilization, defocus mode, and mic to the test.

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

Rohou, A. & Grigorieff, N. CTFFIND4: fast and accurate defocus estimation from electron micrographs.

From Nature ● Nov. 7, 2017

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

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

From Teething Ring by Francis, Dick

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

Suddenly, his gaze defocused and he looked aside, to stare unseeingly at the floor.

From Indirection by Freas, Kelly

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