[ noo-tree-noh, nyoo- ]
/ nuˈtri noʊ, nyu- /

noun, plural neu·tri·nos.Physics.

any of the massless or nearly massless electrically neutral leptons. There is a distinct kind of neutrino associated with each of the massive leptons.



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Origin of neutrino

<Italian (1933), equivalent to neutr(o) neuter, neutral + -ino-ine2; coined by E. Fermi Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

Example sentences from the Web for neutrino

  • The same thing goes for a proton or electron or neutron or even a neutrino.

    By Proxy|Gordon Randall Garrett

British Dictionary definitions for neutrino

/ (njuːˈtriːnəʊ) /

noun plural -nos

physics a stable leptonic neutral elementary particle with very small or possibly zero rest mass and spin 1/2 that travels at the speed of light. Three types exist, associated with the electron, the muon, and the tau particle

Word Origin for neutrino

C20: from Italian, diminutive of neutrone neutron
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

Medical definitions for neutrino

[ nōō-trēnō ]

n. pl. neu•tri•nos

Any of three electrically neutral subatomic particles in the lepton family.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for neutrino

[ nōō-trēnō ]

Any of three electrically neutral subatomic particles with extremely low mass. These include the electron-neutrino, the muon-neutrino, and the tau-neutrino.♦ The study of neutrinos that come to the earth as cosmic rays suggests that neutrinos can transform into each other in a process called neutrino oscillation. For this phenomenon to be theoretically possible, the three neutrinos must have distinct masses; for this reason, many scientists believe that they have mass. See Table at subatomic particle.

A Closer Look

Neutrinos were not observed until 1955, roughly a quarter of a century after the physicist Wolfgang Pauli first hypothesized their existence on theoretical grounds. Pauli was studying certain radioactive decay processes called beta decay, processes now known to involve the decay of a neutron into a proton and an electron. A certain amount of energy that was lost in these processes could not be accounted for. Pauli suggested that the energy was carried away by a very small, electrically neutral particle that was not being detected. (He originally wanted to name the particle a neutron but didn't publish the suggestion, and a few years later the particle we now know as the neutron was discovered and named in print. The Italian physicist Enrico Fermi then coined the term neutrino, which means “little neutron” in Italian.) Neutrinos are hard to detect because their mass, if they indeed have any, is extremely low, and they possess no electric charge; a chunk of iron a few light-years thick would absorb only about half of the neutrinos that struck it. Nevertheless, neutrinos can be detected, and three different types have been distinguished, each of which is associated with a particular lepton (the electron, the muon, and the taon) with which it is often paired in interactions involving the weak force. Recent analysis of neutrinos emanated by the Sun has suggested that each type of neutrino can spontaneously turn into one of the others in a process of neutrino oscillation, and for theoretical reasons this in turn would require that neutrinos have mass. If so, then despite their light weight, their abundance may in fact mean that neutrinos contribute significantly to the overall mass of the universe.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for neutrino

[ (nooh-tree-noh) ]

An electrically neutral particle that is often emitted in the process of radioactive decay of nuclei. Neutrinos are difficult to detect, and their existence was postulated twenty years before the first one was actually discovered in the laboratory. Millions of neutrinos produced by nuclear reactions in the sun pass through your body every second without disturbing any atoms.

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.