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

This could be groundbreaking as atomic nuclei are more stable than electrons, and less affected by things like temperature. —Christopher McFadden, Interesting Engineering, 12 Apr. 2026

To trace the solar events that caused these auroras, Miyahara and her colleagues looked for spikes of telltale atomic variations trapped in 13th-century tree rings, using Medieval literature to guide their search. —Jacek Krywko, Scientific American, 10 Apr. 2026

But the atomic collective is the living present, not ancient history – and a future that any new testing will necessarily produce. —Magdalena Stawkowski, The Conversation, 8 Apr. 2026

At the nearly 17-mile-long circular particle accelerator, the Large Hadron Collider (LHC) that sits deep below the French Alps, CERN scientists recreated the quark-gluon plasma by smashing together atomic nuclei of iron at near-light speed. —Robert Lea, Space.com, 8 Apr. 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