(1):
(n.) The smallest particle of matter that can enter into combination; one of the elementary constituents of a molecule.
(2):
(n.) An ultimate indivisible particle of matter.
(3):
(n.) An ultimate particle of matter not necessarily indivisible; a molecule.
(4):
(n.) A constituent particle of matter, or a molecule supposed to be made up of subordinate particles.
(5):
(n.) Anything extremely small; a particle; a whit.
(6):
(v. t.) To reduce to atoms.