serum

[ seer-uhm ]

noun

, plural se·rums, se·ra [seer, -, uh].

1. the clear, pale-yellow liquid that separates from the clot in the coagulation of blood; blood serum.
2. immune serum.
3. any watery animal fluid.
4. the thin, clear part of the fluid of plants.
5. milk whey.

serum

/ ˈsɪərəm /

noun

1. See blood serum
2. antitoxin obtained from the blood serum of immunized animals
3. physiol zoology clear watery fluid, esp that exuded by serous membranes
4. a less common word for whey

serum

/ sîr′əm /

, Plural serums

1. See blood serum
2. Blood serum extracted from an animal that has immunity to a particular disease. The serum contains antibodies to one or more specific disease antigens, and when injected into humans or other animals, it can transfer immunity to those diseases.

Derived Forms

• ˈserumal, adjective

Other Words From

• serum·al adjective

Word History and Origins

Origin of serum¹

1655–65; < Latin: whey

Word History and Origins

Origin of serum¹

C17: from Latin: whey

Example Sentences

Hint: It can’t be found at the bottom of a serum bottle or at some luxury doctor’s office.

From Los Angeles Times

Influencers excitedly wonder what eyeliner, serum or hand cream will be behind door one, and gush over the beautiful box it has come in.

From BBC

Even just my morning routine and night routine, which is very simple: a cleanser, a serum and a moisturizer and sunscreen — that feels really meditative to me.

From Los Angeles Times

The serum works wonders, but there’s a hyper-caveat.

From Salon

Next up was a hydrating serum.

From Los Angeles Times

Related Words

• antibody