P'ARTICLE, noun [Latin particula, from pars, part.]

1. A minute part or portion of matter; as a particle of sand, of lime or of light.

2. In physics, a minute part of a body, an aggregation or collection of which constitutes the whole body or mass. The word is sometimes used in the same sense as atom, in the ancient Epicurean philosophy, and corpuscle in the latter. In this sense, particles are the elements or constituent parts of bodies.

3. Any very small portion or part; as, he has not a particle of patriotism or virtue; he would not resign a particle of his property.

4. In the Latin church, a crumb or little piece of consecrated bread.

5. In grammar, a word that is not varied or inflected; as a preposition.

Organic particles, very minute moving bodies, perceptible only by the help of the microscope, discovered in the semen of animals.