Atom

1. v. t. To reduce to atoms.
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. The smallest particle of matter that can enter into combination; one of the elementary constituents of a molecule.
6. n. Anything extremely small; a particle; a whit.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.