atomic

adjective

atom·​ic ə-ˈtä-mik 

1

a

: of, relating to, or concerned with atoms

atomic physics

b

: nuclear sense 2

atomic energy

2

a

: marked by acceptance of the theory of atomism

b

: atomistic sense 2

3

: minute

4

of a chemical element : existing in the state of separate atoms

atomically

ə-ˈtä-mi-k(ə-)lē 

adverb

Synonyms

• tiny
• minuscule
• miniature
• microscopic
• microscopical

Examples of atomic in a Sentence

made atomic adjustments to the clock's mechanism to keep it from whirring as it ran

Recent Examples on the Web

In a star’s hot, dense core, atomic nuclei smash into each other with immense force, fusing to form new elements. —Jenna Ahart, Quanta Magazine, 2 July 2025

Iran’s Deputy Foreign Minister Majid Takht-Ravanchi told the BBC that Tehran wanted to return to negotiations over its atomic program, which had restarted before the Israeli-US raids. —Semafor Events, semafor.com, 30 June 2025

Yet could a new coalition of European confederates actually produce a nuclear stockpile capable of containing Russia, which holds the planet’s most colossal atomic armory? —Kevin Holden Platt, Forbes.com, 30 June 2025

Trump announced a ceasefire this week between Iran and Israel following U.S. military strikes on Iranian nuclear sites that followed Israel's Operation Rising Lion aimed at curbing Tehran's ability to make an atomic weapon. —Brendan Cole, MSNBC Newsweek, 28 June 2025

Word History

First Known Use

1678, in the meaning defined at sense 1a

Phrases Containing atomic

• atomic bomb
• atomic clock
• atomic energy
• atomic force microscope
• atomic layer deposition
• atomic mass
• atomic mass unit
• atomic number
• atomic pile
• atomic reactor
• atomic theory
• atomic weight
• gram-atomic weight

Rhymes for atomic

• adamic
• anomic
• islamic
• meramec
• tokamak
• anatomic
• antidromic
• astronomic
• autonomic
• cryptogamic
• diatomic
• economic

Kids Definition

atomic

adjective

atom·​ic ə-ˈtäm-ik 

1

: of, relating to, or concerned with atoms, atomic bombs, or nuclear energy

atomic physics

the atomic age

atomic energy

2

: extremely small

3

: found in the state of separate atoms

atomic hydrogen