Simple Definition of atom
: the smallest particle of a substance that can exist by itself or be combined with other atoms to form a molecule
: a very small amount of something
Full Definition of atom
1 : one of the minute indivisible particles of which according to ancient materialism the universe is composed
2 : a tiny particle : bit
3 : the smallest particle of an element that can exist either alone or in combination
4 : the atom considered as a source of vast potential energy
Examples of atom in a sentence
There is not an atom of truth to what he said.
<give me just one atom of information about the novel's surprise ending>
Origin and Etymology of atom
Middle English, from Latin atomus, from Greek atomos, from atomos indivisible, from a- + temnein to cut
First Known Use: 15th century
ATOM Defined for Kids
History for atom
The English word atom came from a Greek word atomos, meaning “not able to be divided.” Ancient Greek philosophers believed that matter could only be divided to the very smallest particles, atoms, which could not be further divided. Modern science revived the atom idea, but it was discovered that even atoms could be split, and that doing so produced great amounts of energy.
Learn More about atom
Seen and Heard
What made you want to look up atom? Please tell us where you read or heard it (including the quote, if possible).