Definitions
1.NounThe smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons. .mw-parser-output .defdate{font-size:smaller}
2.NounA hypothetical particle posited by Greek philosophers as an ultimate and indivisible component of matter.
3.NounThe smallest, indivisible constituent part or unit of something.
4.NounIn logical atomism, a fundamental fact that cannot be further broken down.
5.NounThe smallest medieval unit of time, equal to fifteen ninety-fourths of a second.
6.NounA mote of dust in a sunbeam.
7.NounA very small amount; a whit.
8.NounAn individual number or symbol, as opposed to a list; a scalar value.
9.NounAn integer representing a particular string.
10.NounA non-zero member of a partially ordered set that has only zero below it (assuming that the poset has a least element, its "zero")."In a Venn diagram, an atom is depicted as an area circumscribed by lines but not cut by any line."
11.NounAn element of a set that is not itself a set; an urelement.
12.NounAn age group division in hockey for nine- to eleven-year-olds.