Main Entry:

at·om

Pronunciation:

\ˈa-təm\

Function:

noun

Etymology:

Middle English, from Latin atomus, from Greek atomos, from atomos indivisible, from a- + temnein to cut

Date:

15th century

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