achromatic

American  

[ak-ruh-mat-ik, ey-kruh-] / ˌæk rəˈmæt ɪk, ˌeɪ krə- /

adjective

1. Optics.

   1. free from color.

   2. able to emit, transmit, or receive light without separating it into colors.

2. Biology. (of a cell structure) difficult to stain.

3. Music. without accidentals or changes in key.

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achromatic British  

/ ˌækrəˈmætɪk, əˈkrəʊməˌtɪzəm, əˌkrəʊməˈtɪsɪtɪ /

adjective

1. without colour

2. capable of reflecting or refracting light without chromatic aberration

3. cytology

   1. not staining with standard dyes

   2. of or relating to achromatin

4. music

   1. involving no sharps or flats

   2. another word for diatonic

5. denoting a person who is an achromat

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achromatic Scientific  

/ ăk′rə-măt′ĭk /

1. Designating color perceived to have zero saturation and therefore no hue, such as neutral grays, white, or black.

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Other Word Forms

• achromatically adverb
• achromatism noun

Etymology

Origin of achromatic

First recorded in 1760–70; a- ⁶ + chromatic

Explanation

Use the adjective achromatic to describe something that's colorless, like a dull winter sky. When something is without a color or hue, it is achromatic. Gray urban landscapes and the black surface of a lake on a starless night could both be described as achromatic. In physics, the word achromatic is a bit more complicated, meaning "able to reflect light without it separating into colors." The Greek root word is akhrōmatikos, "colorless," combining the prefix a,"without," and khrōma, "color."

Example Sentences

This work moves achromatic metasurfaces beyond single-channel correction and into the realm of fully independent dual-spin meta-optics.

From Science Daily • Feb. 5, 2026

Instead, brown, gray, beige and white are dominant, an achromatic palette whose gloomy drabness is only relieved by the surprisingly wide variety of neutrals the artist employs.

From Los Angeles Times • Jul. 31, 2023

Unlike some of the artist’s best-known works, which wow with saturations and transformations of color, “Avaar” is achromatic — using only white light.

From New York Times • Oct. 19, 2022

The moneyed, achromatic 2010s could give way to a more fascinating and unpredictable cultural landscape, with once marginalized communities asserting themselves.

From The Guardian • Jun. 22, 2020

The principal’s office was a cramped, achromatic cubicle separated from the library door by a glass trophy case that overflowed with the gilded booty of athletics earned over the past thirty years.

From "The Great Santini" by Pat Conroy