[ dim-er ]
/ ˈdɪm ər /


a person or thing that dims.
Also called dimmer switch. a rheostat or similar device by which the intensity of an electric light may be varied.
  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

Definition for dimmer (2 of 2)

Origin of dim

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

Related forms

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

British Dictionary definitions for dimmer (1 of 2)


/ (ˈdɪmə) /


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

British Dictionary definitions for dimmer (2 of 2)


/ (dɪm) /

adjective dimmer or dimmest

verb dims, dimming or dimmed

Derived Forms

dimly, 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

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.