Definition of "fermion" [fermion]

• A particle, such as an electron, proton, or neutron, having half-integral spin and obeying statistical rules requiring that not more than one in a set of identical particles may occupy a particular quantum state. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "At low energies the Higgs gets a vacuum expectation value, and acts like a mass term, converting the left-handed fermion into a right-handed fermion, which is what you want."
• "The paper laid the basis for describing one of the two categories of the elementary particles that make up an atom - one was boson, and the other came to be known as fermion, after the Italian physicist Enrico Fermi."
• "Assuming that this is no error, then the term "fermion" is ambiguous between elementary particle and composite particle."