: any of several small petrels (genus Pachyptila of the family Procellariidae) of the southern hemisphere that are bluish gray above and white below
: prion protein
A prion is a protein of unknown function that resides on the surface of brain cells.—
Sidney Perkowitz
Sidney Perkowitz
especially
: an abnormal form of prion protein that in mammals includes pathogenic forms which arise sporadically, as a result of genetic mutation, or by transmission (as by ingestion of infected tissue) and which upon accumulation in the brain cause a prion disease (such as bovine spongiform encephalopathy or Creutzfeldt-Jakob disease)
Abnormal proteins, known as prions, may trigger mad-cow disease simply by coming into contact with healthy proteins in the brain. —Time
Time … the infectious prion conformation replicates itself in a host by catching the 'benign' host prion protein and forcing it into the infectious conformation. —Roland Riek
Roland Riek Examples of prion in a Sentence
Recent Examples on the Web
Jake Parks, Discover Magazine, 5 Nov. 2024
This new medical paradigm impacted not only how external threats were imagined—the hordes of viruses, spores and prions who now appeared to be always threatening to break through our defences—but also how the internal world of the body was envisioned.
—Elsa Richardson, TIME, 3 Oct. 2024
Infectious agents known as prions cause chronic wasting disease.
—George Petras, USA TODAY, 29 Apr. 2024
However, because the FDA mandates the removal of all tissues shown to carry the prions — such as brains and spinal cords — from poultry diets, the risk is reduced.
—Susanne Rust, Los Angeles Times, 18 Apr. 2024
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Noun
What Causes Chronic Wasting Disease? CWD is caused by infectious proteins called prions.
—Jake Parks, Discover Magazine, 5 Nov. 2024
This new medical paradigm impacted not only how external threats were imagined—the hordes of viruses, spores and prions who now appeared to be always threatening to break through our defences—but also how the internal world of the body was envisioned.
—Elsa Richardson, TIME, 3 Oct. 2024
Infectious agents known as prions cause chronic wasting disease.
—George Petras, USA TODAY, 29 Apr. 2024
However, because the FDA mandates the removal of all tissues shown to carry the prions — such as brains and spinal cords — from poultry diets, the risk is reduced.
—Susanne Rust, Los Angeles Times, 18 Apr. 2024
See all Example Sentences for prion
Dictionary Entries Near prion
Cite this Entry
“Prion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/prion. Accessed 29 Nov. 2024.
Copy CitationMedical Definition
prion
noun
pri·on
ˈprē-ˌän 
: any of various infectious proteins that are abnormal forms of normal cellular proteins, that proliferate by inducing the normal protein to convert to the abnormal form, and that in mammals include pathogenic forms which arise sporadically, as a result of genetic mutation, or by transmission (as by ingestion of infected tissue) and which upon accumulation in the brain cause a prion disease
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