dim

¹ American  

[dim] / dɪm /

adjective

dimmer, dimmest

1. not bright; obscure from lack of light or emitted light.

   a dim room; a dim flashlight.

2. not seen clearly or in detail; indistinct.

   a dim object in the distance.

3. not clear to the mind; vague.

   a dim idea.

   Synonyms:

   hazy, fuzzy, indistinct, indefinite, faint, unclear

4. not brilliant; dull in luster.

   a dim color.

5. not clear or distinct to the senses; faint.

   a dim sound.

6. not seeing clearly.

   eyes dim with tears.

7. tending to be unfavorable; not likely to happen, succeed, be favorable, etc..

   a dim chance of winning.

8. not understanding clearly.

9. rather stupid; dim-witted.

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verb (used with object)

dimmed, dimming

1. to make dim or dimmer.

   Synonyms:

   cloud, darken

2. to switch (the headlights of a vehicle) from the high to the low beam.

verb (used without object)

dimmed, dimming

1. to become or grow dim or dimmer.

   Synonyms:

   fade, dull

verb phrase

1. dim out (in wartime) to reduce the night illumination of (a city, ship, etc.) to make it less visible from the air or sea, as a protection from enemy aircraft or ships.

idioms

1. take a dim view of, to regard with disapproval, skepticism, or dismay.

   Her mother takes a dim view of her choice of friends.

dim. ² American  

abbreviation

1. (in prescriptions) one-half.

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dim. ³ American  

abbreviation

1. dimension.

2. diminish.

3. diminuendo.

4. diminutive.

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dim British  

/ dɪm /

adjective

1. badly illuminated

   a dim room

2. not clearly seen; indistinct; faint

   a dim shape

3. having weak or indistinct vision

   eyes dim with tears

4. lacking in understanding; mentally dull

5. not clear in the mind; obscure

   a dim memory

6. lacking in brilliance, brightness, or lustre

   a dim colour

7. tending to be unfavourable; gloomy or disapproving (esp in the phrase take a dim view )

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verb

1. to become or cause to become dim

2. (tr) to cause to seem less bright, as by comparison

3. Also called (in Britain and certain other countries): dip.  (tr) to switch (car headlights) from the main to the lower beam

dim More Idioms  

1. see take a dim view.

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Usage

What does dim mean? Dim describes something as lacking light or having a weak brightness, as in a dim flashlight or a dim tunnel. Dim also describes things that are unclear, because of poor visibility, a weak understanding, or a more general lack of clarity, as in a dim shape in the distance, a dim noise, or a dim knowledge of math. Dim also describes having weak or poor vision, as in Jane’s eyes were dim with tears. Dim can be used to mean lacking mental ability or having low intelligence. However, this is almost always considered insulting. As a verb, dim means to make something dim or less bright, as in He dimmed the lights. It can also be used to mean to grow dim or dimmer, as in The noise of the engine dimmed as the car drove out of sight. Example: Although the tunnel was dim, the faint candlelight guided the miner back to the surface.

Related Words

See dark.

Other Word Forms

• dimly adverb
• dimmable adjective
• dimness noun
• undim adjective
• undimly adverb
• undimmed adjective

Etymology

Origin of dim¹

before 1000; Middle English, Old English dim ( me ), cognate with Old Frisian dim, Old Norse dimmr

Origin of dim.²

From the Latin word dīmidius

Explanation

Dim has several meanings related to a lack of light, hope, or knowledge. A room that is not well lit is dim, a slow thinker is dim, and when life looks hopeless, your prospects are dim. To dim a light is to dull it, like by putting a shade over it. A vague idea without a lot of specifics is also dim, since it's hard to see or understand the idea. Someone who's not very bright is dim or a dimwit. When things are hopeless, they're dim too. For example, if a football team is losing by fifty points, their chances of winning are dim.

Example Sentences

These include Cepheid variable stars, which brighten and dim in predictable ways, red giant stars with known brightness, Type Ia supernovae, and certain galaxy types.

From Science Daily • Apr. 12, 2026

None of that meant a thing to Clinton’s election odds either, although her loss did nothing to dim the womanist fury embedded in Jackson’s song.

From Salon • Apr. 11, 2026

But if it’s a solo night, it’s like candles, lavender bubbles, lights are dim, jazz music is playing in the background, like Billie Holiday, and that is the ultimate reset.

From Los Angeles Times • Apr. 10, 2026

At a viewpoint overlooking Chiang Mai, the city skyline was almost entirely obscured, with only faint outlines of hills visible through a dense grey haze and a dim orange sun hanging in the sky.

From Barron's • Apr. 3, 2026

I shoot baskets in the dim back-door light.

From "The Tenth Mistake of Hank Hooperman" by Gennifer Choldenko

Related Words

• blurred
• cloudy
• dark
• dingy
• dull
• faint
• fuzzy
• gloomy
• lackluster
• murky
• shadowy
• vague