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 of atomic

• tiny
• minuscule
• microscopic
• miniature

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

The pact's termination left no caps on the two largest atomic arsenals for the first time in more than a half-century, fueling fears of an unconstrained nuclear arms race. —Vladimir Isachenkov The Associated Press, Arkansas Online, 6 Feb. 2026

The pact’s termination left no caps on the two largest atomic arsenals for the first time in more than a half-century, fueling fears of an unconstrained nuclear arms race. —Vladimir Isachenkov, Los Angeles Times, 5 Feb. 2026

The technique could also be extended to collisions involving atomic nuclei and to experiments at the future Electron-Ion Collider. —Georgina Jedikovska, Interesting Engineering, 5 Feb. 2026

With no concrete plans for a similar nonproliferation pact to replace it, is the world now on the cusp of a Cold War-style atomic arms race? —Rafi Schwartz, TheWeek, 5 Feb. 2026

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