a minute portion, piece, fragment, or amount; a tiny or very small bit: a particle of dust; not a particle of supporting evidence.
2.
Physics.
a.
one of the extremely small constituents of matter, as an atom or nucleus.
b.
an elementary particle, quark, or gluon.
c.
a body in which the internal motion is negligible.
3.
a clause or article, as of a document.
4.
Grammar.
a.
(in some languages) one of the major form classes, or parts of speech, consisting of words that are neither nouns nor verbs, or of all uninflected words, or the like.
b.
such a word.
c.
a small word of functional or relational use, as an article, preposition, or conjunction, whether of a separate form class or not.
5.
Roman Catholic Church. a small piece of the Host given to each lay communicant in a Eucharistic service.
An uninflected item that has grammatical function but does not clearly belong to one of the major parts of speech, such as up in He looked up the word or to in English infinitives.
In some systems of grammatical analysis, any of various short function words, including articles, prepositions, and conjunctions.
A small piece of a consecrated host.
One of the smaller, individual hosts.
Linguistics
An uninflected item that has grammatical function but does not clearly belong to one of the major parts of speech, such as up in He looked up the word or to in English infinitives.
In some systems of grammatical analysis, any of various short function words, including articles, prepositions, and conjunctions.
A small piece of a consecrated host.
One of the smaller, individual hosts.
Roman Catholic Church
A small piece of a consecrated host.
One of the smaller, individual hosts.
Archaic A small division or section of something written, such as a clause of a document.
[Middle English, from Latin particula, diminutive of pars, part-, part; see part.]
1380, "small part or division of a whole," from L. particula "little bit or part," dim. of pars (gen. partis), see part (n.). In construction, particle board (1957) is so called because it is made from chips and shavings of wood.
Main Entry: elementary particle Function: noun 1: any of the particles of which matter and energy are composed or which mediate the fundamental forces of nature;especially: one (as the photon or the electron) whose existence has not been attributed to the combination of other more fundamental entities 2: one of thestructural units of mitochondrial cristae that are observable by the electron microscope usually as spheres or stalked spheres and are prob. the seat of fundamental energy-producing reactions
Main Entry: par·ti·cle Pronunciation: 'pärt-i-k&l Function: noun 1: one of the minute subdivisions of matter (as an atom ormolecule); also:ELEMENTARY PARTICLE 2: a minute quantity or fragment
A knoblike body that appears on the luminal surfaces of mitochondrial cristae and is believed to be involved with the electron transport system.
Any of the subatomic particles that compose matter and energy, especially one hypothesized or regarded as an irreducible constituent of matter. Also called fundamental particle.
elementary particle (ěl'ə-měn'tə-rē) Pronunciation Key
Any of the smallest, discrete entities of which the universe is composed, including the quarks, leptons, and gauge bosons, which are not themselves made up of other particles. Most types of elementary particles have mass, though at least one, the photon, does not. Also called fundamental particle. See also composite particle, subatomic particle.
Our Living Language: The smallest known units of matter, or elementary particles, are classified under three distinct groups: the quarks, the leptons, and the bosons. The six types or "flavors" of quarks are the up quark, the down quark, the charm quark, the strange quark, the top quark and the bottom quark. All quarks have mass, electric charge, and a special kind of charge called color, and each is associated with a distinct antiparticle, making twelve quarks in all. The leptons include the electron, the muon, the tau particle, the electron neutrino, the muon neutrino, and the tau neutrino. These particles also have distinct antiparticles; the neutrinos are electrically neutral and, if they do have mass, are extremely light. Each of these elementary particles interacts with other elementary particles through one or more forces: the electromagnetic force (between particles with electric charge), the strong force (between particles with color charge, such as the quarks), the weak force (between all leptons and quarks), and the gravitational force (between all particles). These forces are mediated by yet another set of elementary particles, the gauge bosons: when two particles interact, they exchange one or more gauge bosons. The gauge bosons include the W and Z bosons, which mediate the weak nuclear force, the gluon, which mediates the strong nuclear force, and the photon, which mediates the electromagnetic force. The hypothetical graviton, which would mediate the gravitational force, has not been isolated. A sixth boson, the Higgs boson, is believed to interact with the other elementary particles in such a way as to impart mass to them; it too has not been experimentally isolated. Though these particles are believed to be elementary, they can under certain circumstances change into other elementary particles. In beta decay, for example, an up quark turns into a down quark, emitting an electron and an electron antineutrino in the process. All known forms of matter and energy are made of combinations of and interactions between elementary particles; atoms, for example, are made of electrons orbiting a nucleus composed of quarks bound together into larger particles, the protons and neutrons. Whether these particles might themselves be composed of more fundamental building blocks is an open question, and the construction of a "theory of everything" that would explain the properties of all of the known particles and forces remains the ultimate goal for modern physics.
[pahr-ti-kuh
l] 
