Dictionary.com
definitions
  • synonyms

prion1

[prahy-on]
See more synonyms on Thesaurus.com
noun
  1. any of several petrels of the genus Pachyptila, located in the oceans of the Southern Hemisphere and having serrated edges on the bill.
Show More

Origin of prion1

1840–50; < New Latin < Greek príōn a saw

prion2

[pree-on, prahy‐]
noun
  1. a tiny proteinaceous particle, likened to viruses and viroids, but having no genetic component, thought to be an infectious agent in bovine spongiform encephalopathy, Creutzfeldt-Jakob disease, and similar encephalopathies.
Show More

Origin of prion2

1980–85; pr(oteinaceous) + i(nfectious) + -on1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for prion

Contemporary Examples

Historical Examples


British Dictionary definitions for prion

prion1

noun
  1. any of various dovelike petrels of the genus Pachyptila of the southern oceans that have a serrated bill
Show More

Word Origin

C19: New Latin, from Greek priōn a saw

prion2

noun
  1. a protein in the brain, an abnormal form of which is thought to be the transmissable agent responsible for certain spongiform encephalopathies, such as BSE, scrapie, Creutzfeldt-Jakob disease, and kuru
Show More

Word Origin

C20: altered from pro (teinaceous) in (fectious particle)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for prion

n.

petrel-like bird, 1848, from Greek prion "a saw," related to priein, prizein "to saw, to be cut in pieces." So called for its bill.

Show More
Online Etymology Dictionary, © 2010 Douglas Harper

prion in Medicine

prion

(prēŏn)
n.
  1. A microscopic protein particle, apparently self-replicating despite the absence of nucleic acid, thought to be the infectious agent that causes Creutzfeld-Jakob disease and certain other neurodegenerative diseases.
Show More
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

prion in Science

prion

[prēŏn, prī-]
  1. A particle of protein that is thought to be able to self-replicate and to be the agent of infection in a variety of diseases of the nervous system, such as mad cow disease. Prion replication (in which strings of amino acids are reproduced) stands as an exception to a central tenet of biology stating that only nucleic acids, such as DNA, can self-replicate. The mechanism of prion replication is not clearly understood.
Show More
A Closer Look: In 1997 Stanley Prusiner was awarded the Nobel Prize for physiology or medicine for his theory that a deviant form of a harmless protein could be an infectious agent, a transmitter of disease. Named prions (short for proteinaceous infectious particle), these misshapen proteins cause healthy proteins to misfold, fatally clumping together in the brain. Unlike other disease-causing agents, prions lack genetic material (DNA and RNA). Neurodegenerative prion diseases are often called spongiform encephalopathies because they leave the brain riddled with holes like a sponge. In animals, prion diseases include scrapie in sheep and bovine spongiform encephalopathy, commonly known as mad cow disease in cattle. In humans, diseases such as kuru and Creutzfeldt-Jakob disease (CJD) are also thought to be caused by prions. All the diseases are characterized by loss of motor control, dementia, paralysis, and eventual death due to massive destruction of brain tissue. Humans are thought to contract prion disease most commonly by eating prion-contaminated flesh. Kuru, a rare and fatal brain disorder, brought prion disease to the forefront. First described in the 1950s, kuru was most common among the Fore people of Papua New Guinea, who had a custom of eating the brains of their dead during funeral feasts. It is speculated that a tribe member developed CJD, his or her contaminated brain tissue was ingested, and the disease spread. Kuru reached epidemic levels in the 1960s, but the disease declined after the government discouraged the practice of cannibalism and now it has almost completely disappeared.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

prion in Culture

prion

[(pree-on)]

A protein that not only folds into an unusual shape itself, but also seems to have the ability to cause other proteins to change their shape as well. For a long time, scientists were skeptical that prions existed, but now most accept them.

Show More

Note

Prions are thought to be the cause of mad cow disease.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.