prion

noun (1)
pri·​on | \ ˈprī-ˌän How to pronounce prion (audio) \

Definition of prion

 (Entry 1 of 2)

: any of several small petrels (genus Pachyptila of the family Procellariidae) of the southern hemisphere that are bluish gray above and white below

prion

noun (2)
pri·​on | \ ˈprē-ˌän How to pronounce prion (audio) \

Definition of prion (Entry 2 of 2)

: prion protein A prion is a protein of unknown function that resides on the surface of brain cells.— 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 … 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

First Known Use of prion

Noun (1)

1848, in the meaning defined above

Noun (2)

1982, in the meaning defined above

History and Etymology for prion

Noun (1)

New Latin, from Greek priōn saw, from priein to saw; from its sawlike bill

Noun (2)

proteinaceous + infectious + -on entry 2

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Cite this Entry

“Prion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/prion. Accessed 21 Jun. 2021.

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More Definitions for prion

prion

noun
pri·​on | \ ˈprē-ˌän How to pronounce prion (audio) \

Medical Definition of prion

: 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

More from Merriam-Webster on prion

Britannica.com: Encyclopedia article about prion

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