serum

noun
se·​rum | \ ˈsir-əm How to pronounce serum (audio) \
plural sera\ ˈsir-​ə How to pronounce serum (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 Sam met Isaiah Bradley, known in Marvel comics as the first Black Captain America, who, in the MCU, was a Black man who faked his death after being subjected to torturous experimentation with the super-solder serum. Ew Staff, EW.com, "What to Watch this Weekend: RuPaul's Drag Race season 13 crosses the finish line," 23 Apr. 2021 This multi-tasking serum is a must for any anti-aging regimen. Jennifer Aldrich, Better Homes & Gardens, "The 12 Best Mother's Day Gifts to Give to the Beauty Lover This Year," 15 Apr. 2021 Now, Perkins is embarking on her next ambitious endeavour with her new skin-care line, Dezi Skin, which went live today with a fragrance-free vitamin C serum called Claro Que C. Thatiana Diaz, refinery29.com, "Desi Perkins Pays Homage To Her Mexican Roots With Her Skin-Care Launch," 9 Apr. 2021 Perkins decided to kick off her new brand with a vitamin C serum because dark spots are something she's been dealing with for a while. Angela Trakoshis, Allure, "YouTuber Desi Perkins Just Launched Skin Care," 8 Apr. 2021 So this serum can help reduce signs of aging in two gentle ways: with chemical exfoliation and with peptides. Sarah Jacoby, SELF, "The New Drunk Elephant Serum Is an Easy Way to Level Up Your Antiaging Skin-Care Routine," 2 Apr. 2021 While Steve Rogers was infused with super-soldier serum during World War II, John Walker is a different Cap for the times. Brian Truitt, USA TODAY, "Spoilers! Meet the new Captain America in Marvel's 'The Falcon and the Winter Soldier'," 20 Mar. 2021 La Roche-Posay Pave the way to younger-looking, supple skin with a plumping serum with hyaluronic acid, one of the best antiaging ingredients. Kaitlyn Yarborough, Southern Living, "Beauty Girls Swear By This Under-the-Radar Drugstore Cream for the Most Enviable Dewy Glow," 19 Mar. 2021 Well, first he was injected with super soldier serum during World War II. Eliana Dockterman, Time, "Everything You Need to Know About The Falcon and the Winter Soldier," 19 Mar. 2021

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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Last Updated

26 Apr 2021

Cite this Entry

“Serum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/serum. Accessed 7 May. 2021.

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More Definitions for serum

serum

noun

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 serum (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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More from Merriam-Webster on serum

Thesaurus: All synonyms and antonyms for serum

Nglish: Translation of serum for Spanish Speakers

Britannica English: Translation of serum for Arabic Speakers

Comments on serum

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