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

Treating noise as a simple blur can lead to unrealistic expectations about the true capabilities of quantum computing.

From Science Daily • Apr. 6, 2026

The five-person cast roams the room, sitting at various circular tables to blur the lines between script and improvisation.

From Los Angeles Times • Mar. 18, 2026

But as the lines blur further, will clubs keep that stance?

From BBC • Mar. 2, 2026

I was so dehydrated that my vision had started to blur.

From The Wall Street Journal • Mar. 1, 2026

I watch until my eyes blur and the stick disappears into the folds of the current.

From "Code Name Kingfisher" by Liz Kessler

Related Words

• darken
• dim
• muddy
• obscure
• soften