sputum

American  

[spyoo-tuhm] / ˈspyu təm /

noun

plural

sputa

1. matter, as saliva mixed with mucus or pus, expectorated from the lungs and respiratory passages.

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sputum British  

/ ˈspjuːtəm /

noun

1. a mass of salivary matter ejected from the mouth

2. saliva ejected from the mouth mixed with mucus or pus exuded from the respiratory passages, as in bronchitis or bronchiectasis

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Etymology

Origin of sputum

1685–95; < Latin spūtum, noun use of neuter of spūtus, past participle of spuere to spit, equivalent to spū- variant stem + -tus past participle suffix

Compare meaning

How does sputum compare to similar and commonly confused words? Explore the most common comparisons:

• sputum vs. mucus

Explanation

Sputum is the gross stuff that you cough up when you're sick and congested. Sputum is your saliva mixed with mucus from your lungs. Examining a patient's sputum is one way for a doctor to tell if she might have an infection, rather than just a cold. A yellow or greenish color to the sputum someone coughs up is a sign of infection, while clear sputum usually means all is well. The word sputum shares a root with spew, the Latin verb spuere, "to spit."

Example Sentences

"It's meant to break up sputum, but kids under two can't spit it out, so the mucus can be aspirated into the lungs, causing pneumonia - yet it is still prescribed."

From BBC • Oct. 7, 2025

The living material incorporates multiple microbial communities and key nutritional and chemical factors that promote bacterial growth and exhibit physical properties mimicking those of biofilms from CF sputum.

From Science Daily • Nov. 21, 2023

They’ve also helped health clinics in Africa diagnose people with tuberculosis, detecting the bacteria in the sputum samples of 25,000 patients.

From Seattle Times • Apr. 18, 2023

But were these tree bubbles — or tree sputum, as I came to call them — actually insect eggs?

From Washington Post • Feb. 20, 2023

He tells me how TB is such a deceptive disease; it doesn’t always reveal itself by a sputum culture, as it did for the father.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French