See more synonyms for dimmer on Thesaurus.com
  1. a person or thing that dims.
  2. Also called dimmer switch. a rheostat or similar device by which the intensity of an electric light may be varied.
  3. dimmers,
    1. the low-beam headlights of an automobile or truck.
    2. the small, parking lights of an automobile.

Origin of dimmer

First recorded in 1815–25; dim + -er1


adjective, dim·mer, dim·mest.
  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.
  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.
verb (used with object), dimmed, dim·ming.
  1. to make dim or dimmer.
  2. to switch (the headlights of a vehicle) from the high to the low beam.
verb (used without object), dimmed, dim·ming.
  1. to become or grow dim or dimmer.
Verb Phrases
  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.
  1. take a dim view of, to regard with disapproval, skepticism, or dismay: Her mother takes a dim view of her choice of friends.

Origin of dim

before 1000; Middle English, Old English dim(me), cognate with Old Frisian dim, Old Norse dimmr
Related formsdim·ly, adverbdim·ma·ble, adjectivedim·ness, nounun·dim, adjectiveun·dim·ly, adverbun·dimmed, adjective

Synonyms for dim

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Synonym study

1. See dark.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for dimmer

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British Dictionary definitions for dimmer


  1. a device, such as a rheostat, for varying the current through an electric light and thus changing the illumination
  2. (often plural) US
    1. a dipped headlight on a road vehicle
    2. a parking light on a car


adjective dimmer or dimmest
  1. badly illuminateda dim room
  2. not clearly seen; indistinct; fainta dim shape
  3. having weak or indistinct visioneyes dim with tears
  4. lacking in understanding; mentally dull
  5. not clear in the mind; obscurea dim memory
  6. lacking in brilliance, brightness, or lustrea dim colour
  7. tending to be unfavourable; gloomy or disapproving (esp in the phrase take a dim view)
verb dims, dimming or dimmed
  1. to become or cause to become dim
  2. (tr) to cause to seem less bright, as by comparison
  3. US and Canadian (tr) to switch (car headlights) from the main to the lower beamAlso called (in Britain and certain other countries): dip
Derived Formsdimly, adverbdimness, noun

Word Origin for dim

Old English dimm; related to Old Norse dimmr gloomy, dark
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for dimmer

1822, agent noun from dim (v.). Of mechanisms for reducing the brightness of electric lights, from 1905.



c.1200, perhaps in Old English, from dim (adj.). Related: Dimmed; dimming.



Old English dimm "dark, gloomy, obscure," from Proto-Germanic *dimbaz (cf. Old Norse dimmr, Old Frisian dim, Old High German timber "dark, black, somber"). Not known outside Germanic. Slang sense of "stupid" is from 1892. Related: Dimly; dimness.

Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with dimmer


see take a dim view.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.