pus

American  

[puhs] / pʌs /

noun

1. a yellow-white, more or less viscid substance produced by suppuration and found in abscesses, sores, etc., consisting of a liquid plasma in which white blood cells are suspended.

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pus British  

/ pʌs /

noun

1. the yellow or greenish fluid product of inflammation, composed largely of dead leucocytes, exuded plasma, and liquefied tissue cells

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pus Scientific  

/ pŭs /

1. A thick, yellowish-white liquid that forms in infected body tissues, consisting of white blood cells, dead tissue, and cellular debris.

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Other Word Forms

• puslike
  adjective

Etymology

Origin of pus

1535–45; < Latin; akin to Greek pýon pus. See pyo-

Explanation

Pus is the yucky yellowish stuff that oozes out of an infected cut or pimple. Medically speaking, pus is made up of various types of white blood cells that have died. Bacteria can cause infections, and when the infected area becomes inflamed, pus often forms and collects under the skin. A boil or pimple full of pus can be painful, and seeing pus in a wound is a sign that you should go to the doctor, who will prescribe antibiotics to treat the infection and may also drain the pus. The Latin pus means "matter from a sore" but also "bitterness or malice."

Example Sentences

Neutrophils are short-lived immune cells that respond aggressively to threats and are a major component of pus.

From Science Daily • Dec. 27, 2025

The medical staff cut his toe open with a scalpel and a milk-like pus came out.

From BBC • Nov. 27, 2023

Necrotizing fasciitis can progress quickly, producing ulcers, blisters, skin discoloration and pus.

From Salon • Sep. 25, 2023

It involved deliberately infecting someone with the disease by pricking someone else’s smallpox pustule, removing some pus, and placing that pus inside an incision on the recipient’s arm or thigh.

From Slate • Sep. 4, 2023

Dr. Frank Hamilton considered the methods to be useful only after pus and blood oozed from a wound.

From "Ambushed!" by Gail Jarrow