serum

1 of 2

noun

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

2 of 2

adjective

: 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
These examples are automatically compiled from online sources to illustrate current usage. Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Noun
Another example is The Face Shop’s viral Mucin Peptide 8 serum — the company now has a vegan exclusive version available on TikTok Shop. Kanika Talwar, WWD, 29 Oct. 2024 This serum has a type of vitamin C known as 3 O ascorbic acid, which works wonders in brightening your skin. Hyphensocial Contributors, Rolling Stone, 25 Oct. 2024
Adjective
Lizzo completes her skincare process with a serum facial sheet mask from Cicapair. Charmaine Patterson, Peoplemag, 24 Oct. 2022 See all Example Sentences for serum 

Word History

Etymology

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

First Known Use

Noun

1651, in the meaning defined at sense 1

Adjective

1876, in the meaning defined above

Time Traveler
The first known use of serum was in 1651

Dictionary Entries Near serum

Cite this Entry

“Serum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/serum. Accessed 14 Nov. 2024.

Kids Definition

serum

noun
se·​rum
ˈsir-əm
plural serums or sera
ˈsir-ə

Medical Definition

serum

1 of 2 noun
se·​rum ˈsir-əm How to pronounce serum (audio)
plural sera -ə How to pronounce serum (audio) or serums
: 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)
b
: a normal or pathological serous fluid (as in a blister)

serum

2 of 2 adjective
: occurring or found in the serum of the blood
serum cholesterol
serum glutamic-oxaloacetic transminase

More from Merriam-Webster on serum

Last Updated: - Updated example sentences
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