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

And that each electron is tiny in mass compared to each proton, neutrons, and atomic nucleus. —Big Think, 16 Oct. 2025

As per the researchers, the results deepen the world’s knowledge at the atomic level. —Georgina Jedikovska, Interesting Engineering, 16 Oct. 2025

Using these new attosecond X-ray laser pulses could allow scientists to study the fastest processes in materials at the atomic-length scale and to discern different elements. —Thomas Linker, The Conversation, 15 Oct. 2025

Unlike nuclear fission which splits atoms of heavy elements, fusion combines two light atomic nuclei, releasing a large amount of energy with much less radioactive waste. —Jeff Young, MSNBC Newsweek, 14 Oct. 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