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

Occasionally, one of these photons strikes a nearby atomic nucleus. —Rupendra Brahambhatt, Interesting Engineering, 28 Mar. 2026

This is the faint thermal afterglow from some 380,000 years after the big bang that was unleashed when the hot, foglike plasma that filled the early universe cooled and cleared as primordial atomic nuclei bonded with free electrons. —Paul M. Sutter, Scientific American, 27 Mar. 2026

The show examines the environmental and human cost of the atomic era through an artistic lens, tracing present day nuclear risk back to its Cold War roots. —Chloe Shrager, Los Angeles Times, 27 Mar. 2026

Cambodia’s latest national strategy signaled an openness to nuclear and Singapore outlined plans last year to study its own atomic potential. —ABC News, 25 Mar. 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