1. Of or pertaining to atoms.
2. Extremely minute; tiny. Atomic philosophy, or doctrine of atoms, a system which assuming that atoms are endued with gravity and motion accounted thus for the origin and formation of all things. This philosophy was first broached by Leucippus, was developed by Democritus, and afterward improved by Epicurus, and hence is sometimes denominated the Epicurean philosophy.
(Science: chemistry) atomic theory, or the doctrine of definite proportions, the weight of the atom of an element as compared with the weight of the atom of hydrogen, taken as a standard.
Origin: cf. F. Atomique.