serum

noun
se·​rum | \ ˈsir-əm How to pronounce serum (audio) \
plural sera\ ˈsir-​ə How to pronounce sera (audio) \ or serums

Definition of serum

 (Entry 1 of 2)

1 : the watery, clear portion of an animal fluid:
a : the clear, yellowish fluid that remains from blood plasma after clotting factors (such as fibrinogen and prothrombin) have been removed by clot formation : blood serum — compare antiserum, convalescent serum
b : a normal or pathological serous fluid (as in a blister)
c : whey
2 : a usually lightweight cosmetic preparation especially for use on the face specifically : a typically water-based, often concentrated preparation that lacks lubricating and thickening agents an antiaging facial serum
3 : the watery part of a plant fluid Latex. This, the natural product of the rubber tree, is a suspension of rubber droplets in a watery serum concentrated and stabilized in such a way that the dry rubber content is between 60 and 70 per cent.— C. A. O'Flaherty — see also truth serum

serum

adjective

Definition of serum (Entry 2 of 2)

: occurring or found in the blood serum serum cholesterol serum antibodies

Examples of serum in a Sentence

Noun The patient was administered serum.
Recent Examples on the Web: Noun After a summer well spent in the sun and sea, turn to Christophe Robin’s new regenerating serum to bring dull lengths back to life. Zoe Ruffner, Vogue, "The Fall Beauty Checklist: 10 New Game-Changing Products to Buy Now," 11 Sep. 2020 Developed with the help of dermatologists, the serum boasts 3 anti-aging powerhouses: vitamin C, hyaluronic acid, and skin-repairing ceramides. Braelyn Wood, Health.com, "The CeraVe Vitamin C Serum Is Already an Amazon Best-Seller—and It’s Only $16," 10 Sep. 2020 That was partly because animal serum created substantial complications when it was used to treat people. Dhruv Khullar, The New Yorker, "It Will Take More Than a Vaccine to Beat COVID-19," 8 Sep. 2020 And though there's a small dose of retinol infused into the serum, my skin never looks red or feels over-sensitized—just rejuvenated, smooth, and better primed for my makeup. Taylore Glynn, Marie Claire, "Why 111Skin's Black Diamond Eye Masks Are Worth It," 24 June 2020 Enter, Kosas' first-ever mascara — which toes the line between a lash serum and a makeup product with ingredients like castor oil, vitamin B5, and peptides at potent concentrations to show your lashes some love. Karina Hoshikawa, refinery29.com, "Lash Serum Meets Mascara In Kosas’ New Beauty Launch," 26 Aug. 2020 Convalescent serum was used to fight the 1918 flu pandemic. Anna Edney, Fortune, "Trump’s push to approve COVID-19 convalescent plasma treatment could delay efforts to better understand it," 24 Aug. 2020 The other experimental option was convalescent serum, antibodies that had been taken from the blood of people who have recovered from COVID-19 and might neutralize the virus that causes it. Monique Brouillette, Scientific American, "Hospitals Experiment with COVID-19 Treatments, Balancing Hope and Evidence," 29 June 2020 Beauty buffs obsessed with all things natural and organic will love Aba Love Apothocary's oil and serum tinctures. Christina Oehler, Health.com, "10 Black-Owned Wellness Companies to Help You Practice Self-Care Right Now," 17 June 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'serum.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of serum

Noun

1651, in the meaning defined at sense 1

Adjective

1876, in the meaning defined above

History and Etymology for serum

Noun

borrowed from Latin, "whey, wheylike fluid," of uncertain origin

Note: Latin serum has been conventionally linked with Greek orós, of identical meaning, and both compared with the Sanskrit verbal base sar-, allegedly meaning " flow" in Vedic texts (hence P. Chantraine in Dictionnaire étymologique de la langue grecque). More recently, however, this interpretation has been rejected, and sar- read as "run off"—hence Vedic Sanskrit ásarat "ran off," prasísarti "lets run, stretches, extends," not akin to sáraḥ "lake, pond" and related words, which describe still water. The Sanskrit etymon has been further compared with Greek hállomai "(I) spring, hop," Latin salīre "to jump" (see sally entry 2). If this is correct the Indo-European base is *sel-, and any connection to serum and orós impossible; these two words are left then without any certain etymology.

Adjective

from attributive use of serum entry 1

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Time Traveler for serum

Time Traveler

The first known use of serum was in 1651

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Statistics for serum

Last Updated

16 Sep 2020

Cite this Entry

“Serum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/serum. Accessed 24 Sep. 2020.

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More Definitions for serum

serum

noun
How to pronounce serum (audio)

English Language Learners Definition of serum

medical : the part of blood that is like water and that contains substances (called antibodies) that fight disease
medical : serum from an animal's blood that can be added to a person's blood to prevent or cure disease
biology : the watery part of a fluid found in a plant

serum

noun
se·​rum | \ ˈsir-əm How to pronounce serum (audio) \

Kids Definition of serum

: the clear liquid part that can be separated from coagulated blood and contains antibodies

serum

noun
se·​rum | \ ˈsir-əm How to pronounce serum (audio) \
plural sera\ -​ə How to pronounce sera (audio) \ or serums

Medical Definition of serum

 (Entry 1 of 2)

: the watery portion of an animal fluid remaining after coagulation:
a(1) : the clear yellowish fluid that remains from blood plasma after fibrinogen, prothrombin, and other clotting factors have been removed by clot formation

called also blood serum

(2) : antiserum
b : a normal or pathological serous fluid (as in a blister)

serum

adjective

Medical Definition of serum (Entry 2 of 2)

: occurring or found in the serum of the blood serum cholesterol serum glutamic-oxaloacetic transminase

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Comments on serum

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