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 (ăk′rə-măt′ĭk, ā′krə-)
1. Designating color perceived to have zero saturation and therefore no hue, such as neutral grays, white, or black.
2. Refracting light without spectral color separation.
3. Biology Difficult to stain with standard dyes. Used in reference to cells or tissues.
4. Music Having only the diatonic tones of the scale.

[From Greek akhrōmatos : a-, without; see a-1 + khrōma, khrōmat-, color.]

ach′ro·mat′i·cal·ly adv.
a·chro′ma·tic′i·ty (-tĭs′ĭ-tē) n.
a·chro′ma·tism (ā-krō′mə-tĭz′əm) n.


1. the total absence of color.
2. the ability to emit, reflect, or transmit light without breaking down into separate colors. Also achromatism.
See also: Color
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.achromaticity - the visual property of being without chromatic colorachromaticity - the visual property of being without chromatic color
visual property - an attribute of vision
achromia - an absence of normal pigmentation especially in the skin (as in albinism) or in red blood cells
References in periodicals archive ?
specular gloss, DOI, and OP) at these four levels of achromaticity.
Cronin, "A biological quarter-wave retarder with excellent achromaticity in the visible wavelength region," Nature Photonics, Vol.
Forth, although cataract surgery dramatically changes chromatic coordinates for achromaticity (Delahunt et al.