blur

American  

[blur] / blɜr /

verb (used with object)

blurred, blurring

1. to obscure or sully (something) by smearing or with a smeary substance.

   The windows were blurred with soot.

2. to obscure by making confused in form or outline; make indistinct.

   The fog blurred the outline of the car.

   Synonyms:

   mask, veil, darken, dim, cloud

3. to dim the perception or susceptibility of; make dull or insensible.

   The blow on the head blurred his senses.

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verb (used without object)

blurred, blurring

1. to become indistinct.

   Everything blurred as she ran.

2. to make blurs.

noun

1. a smudge or smear that obscures.

   a blur of smoke.

2. a blurred condition; indistinctness.

   They could see nothing in the foggy blur.

3. something seen indistinctly.

   The ship appeared as a blur against the horizon.

blur British  

/ ˈblɜːd-, ˈblɜːrɪdlɪ, blɜː /

verb

1. to make or become vague or less distinct

   heat haze blurs the hills

   education blurs class distinctions

2. to smear or smudge

3. (tr) to make (the judgment, memory, or perception) less clear; dim

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noun

1. something vague, hazy, or indistinct

2. a smear or smudge

Other Word Forms

• blurred adjective
• blurredly adverb
• blurredness noun
• blurriness noun
• blurringly adverb
• blurry adjective
• unblurred adjective

Etymology

Origin of blur

First recorded in 1540–50; akin to blear

Explanation

To blur is to make or become unfocused and fuzzy. Crying hard can cause your vision to blur until you wipe your tears away. Heavy smog or early morning fog can blur your view of the city, and two candidates' similar views can blur the differences between their political parties. In both cases, things become indistinct and hazy. You can also call the haze itself a blur: "The whole day was just a blur after the exciting news I got in the morning." In the 16th century, blur meant "smear on the surface of writing."

Example Sentences

Edward would latch onto a tree a few hundred yards down river and hold tight until he was rescued at daybreak, a period that he described as a blur.

From The Wall Street Journal • Apr. 18, 2026

Because it uses a gas of atoms, effects such as Doppler broadening, collisional broadening, and averaging across many atoms can blur the signal.

From Science Daily • Apr. 17, 2026

Sam Altman’s side hustles blur the line between OpenAI’s interests and his own.

From MarketWatch • Apr. 17, 2026

Founder Alvin Ailey’s technical approach to dance combined modern dance, ballet and jazz — among other dance forms — in an attempt to blur the traditional boundaries of the dance world.

From Los Angeles Times • Mar. 24, 2026

His long black hair swirls around him; his toned but rail-thin arms are a blur as he smacks drumsticks on a box of fish tackle, Dad’s lawn mower, and the snowshoes I never finished making.

From "Legendary Frybread Drive-In" by Cynthia Leitich Smith

Related Words

• darken
• dim
• muddy
• obscure
• soften