from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Philosophy The ancient theory of Democritus, Epicurus, and Lucretius, according to which simple, minute, indivisible, and indestructible particles are the basic components of the entire universe.
- n. Philosophy A theory according to which social institutions, values, and processes arise solely from the acts and interests of individuals, who thus constitute the only true subject of analysis.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The ancient Greek theory that all matter is composed of very small indestructible and indivisible particles.
- n. The doctrine that society arises from individuals and that larger structures are unimportant.
from the GNU version of the Collaborative International Dictionary of English
- n. The doctrine of atoms. See Atomic philosophy, under atomic.
from The Century Dictionary and Cyclopedia
- n. The metaphysical or the physical theory of atoms; atomic philosophy or atomic theory. See atomic.
- n. The state of existing as an atom or a unit, or of being composed of atoms or units; individualism.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (psychology) a theory that reduces all mental phenomena to simple elements (sensations and feelings) that form complex ideas by association
- n. (chemistry) any theory in which all matter is composed of tiny discrete finite indivisible indestructible particles
atom + -ism (Wiktionary)