atom

IPA: ˈætʌm

(chemistry, physics) The smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.
(history of science) A hypothetical particle posited by Greek philosophers as an ultimate and indivisible component of matter.
(now generally regarded figuratively) The smallest, indivisible constituent part or unit of something.
(philosophy) In logical atomism, a fundamental fact that cannot be further broken down.
(historical) The smallest medieval unit of time, equal to fifteen ninety-fourths of a second.
A mote of dust in a sunbeam.
A very small amount; a whit.
(computing, programming, Lisp) An individual number or symbol, as opposed to a list; a scalar value.
(mathematics) A non-zero member of a partially ordered set that has only zero below it (assuming that the poset has a least element, its "zero").
(mathematics, set theory) An element of a set that is not itself a set; an urelement.
(Canada, usually attributive) An age group division in hockey for nine- to eleven-year-olds.
a Meitei surname from Manipuri

Examples of "atom" in Sentences

I do think that harnessing the power of the atom is the way to go.
(For convenience, "atom" is included as a special case of molecule).
The energy produced by the breaking down of the atom is a very poor kind of thing.
We now suppose that it is _a rapid movement of electrons from atom to atom_ in the wire or wherever the current is.
While the term atom, therefore, is applicable only to elements, the term molecule is applicable both to elements and compounds.
Thus the term atom indicates not only the constituents of molecules but has a quantitative meaning, the proportional part of the element which enters into compounds.
It was the ancient Greeks who gave us the idea of atoms, fundamental and invisibly small particles of matter, and also the word atom, which means “uncuttable,” “indivisible.”
Coined in ancient Greece, the term atom means “indivisible unit,” and through the nineteenth century, scientists believed that our entire physical universe was composed of these elementary particles.