serum
word
Definition
Serum is the clear, yellowish liquid part of the blood that remains after clotting, often used in medicine and scientific research. It can also refer to a liquid beauty product applied to the skin.
Usage & Nuances
'Serum' is scientific and medical, but also common in skincare ("vitamin C serum"). The medical meaning is uncountable; in cosmetics, can be countable ("a serum"). Don't confuse with 'serum' as a synonym for 'vaccine'—it is not the same.
Example Sentences
The doctor took a sample of serum for testing.
basic
She applies a vitamin C serum to her face every night.
basic
Blood serum contains important proteins.
basic
Some allergy tests are done with serum instead of whole blood.
natural
This new eye serum promises to reduce dark circles.
natural
After the sample clotted, the lab separated the serum for analysis.
natural