1a minute portion of matter:tiny particles of dust
(also subatomic or elementary particle) Physics any of numerous subatomic constituents of the physical world that interact with each other, including electrons, neutrinos, photons, and alpha particles.
Mathematics a hypothetical object having mass but no physical size.
2 [with negative] the least possible amount:he agrees without hearing the least particle of evidence
3 Grammar (in English) any of the class of words such as in, up, off, over, used with verbs to make phrasal verbs.
(in ancient Greek) any of a class of words used for contrast and emphasis, such as de and ge.
