Definition of "desaturate"

(transitive) To cause to become less saturated or unsaturated.  quotations

1. To lessen the saturation of (a colour).  quotations  examples

   Quotations

   • And similarly, they are full of tricks: when the imagined stranger calls your name, the music crescendos romantically; when the video freezes on your laugh, it immediately desaturates the candid photo, making you look old-timey or famous or dead.

     2021 November 1, Haley Nahman, “I got a camera to spy on my cat – and it made me question everything about myself”, in The Guardian‎

2. (chemistry) To convert (a saturated compound) to an unsaturated one.  quotations  examples

   Quotations

   • Mammals, for example, lack the ability to desaturate fatty acids in the n-6 or n-3 position. […] Only plants can desaturate fatty acids at the n-6 or n-3 position, and even among plants, there are species differences.

     2014, Carolyn D. Berdanier, “Nutritional Biochemistry”, in Carolyn D. Berdanier, Johanna T. Dwyer, David Heber, editors, Handbook of Nutrition and Food, 3rd edition, Boca Raton, FL: CRC Press, page 182

(intransitive) To become less saturated or unsaturated.

1. (of a colour) To decrease in saturation.  quotations  examples

   Quotations

   • I am partial to the more threadbare gems and find the more distressed pieces to be the most beautiful. When the rug is worn, the graphic patterns soften slightly, the dye desaturates, and the pile is evenly low so the weave is really visible.

     2017 September 5, Lili Göksenin, “How to Buy, and Live with, a Seriously Good Antique Rug”, in GQ‎

2. (medicine) Of the oxygen saturation level in one's hemoglobin: to decrease, to drop.  quotations  examples

   Quotations

   • "It's all pressure on the heart. Oxygen levels are desaturating, that's not good for the body and the biggest link for untreated sleep apnoea would be heart attacks, strokes and driving accidents," she said.

     2022 May 27, “Hull charity's fears over energy cost impact on breathing machines”, in BBC News‎

3. (medicine, of a person) To undergo a decrease in the oxygen saturation level in the hemoglobin.  quotations  examples

   Quotations

   • After Ida left, Susan deteriorated. The next day, the hospital called to say she kept removing her oxygen mask. “Patient desaturates to 82% without mask, however if held then oxygen improves,” her notes say.

     2022 July 10, Shanti Das, “‘They gave her a bed to die in’: family of woman with Down’s Syndrome denied intensive care seek answers from Covid-19 inquiry”, in The Guardian‎