What does "atom" mean?
The smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.
Atom
/ˈætəm/ name, noun
name, noun ·Common ·High school level
Meaning at a glance
- Primary sense: The smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.
- Grammar: atom is listed as name, noun.
- Nearest alternatives: particle, ace, acid, acidity.
- Useful contrasts: dutch molecuul, german molekül, swedish molekyl.
- Usage evidence: A water molecule has two hydrogen atoms and one oxygen atom.
How to use "atom"
- Start with the primary definition, then check the part of speech before placing the word in a sentence.
- Compare nearby synonyms to make sure "atom" carries the exact meaning, tone, and strength you need.
- Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.
Meaning check
- Does the word fit the sentence's grammar?
- Does it match the intended tone rather than only the dictionary definition?
- Would a simpler synonym be clearer for the reader?
- Is there enough surrounding context to prevent ambiguity?
Source and review context
This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "atom" in a final draft.
If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.
Before you rely on this definition
Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "atom" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "atom" with a nearby alternative so the final choice matches both meaning and reader expectation.
Compare nearby meanings
- Use synonyms when you need a softer, stronger, simpler, or more specific word.
- Use antonyms to check the boundary of the meaning and avoid accidental contrast.
- Use the example sentence to confirm the word behaves naturally in context.
- Keep the original wording when a replacement adds complexity without improving precision.
Definition decision workflow
1. Identify the role
Check whether "atom" is acting as name, noun in your sentence. A definition is only useful when the grammar matches the way the word is being used.
2. Test the nearest option
Compare it with "particle" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.
3. Confirm with context
Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.
Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.
Final meaning check
Before publishing a sentence with "atom", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.
When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.
Definitions
Noun
- 1 The smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.
"Oxygen levels on Earth skyrocketed 2.4 billion years ago, when cyanobacteria evolved photosynthesis: the ability to convert water and carbon dioxide into carbohydrates and waste oxygen using solar energy. The evolutionary precursor of photosynthesis is still under debate, and a new study sheds light. The critical component of the photosynthetic system is the water-oxidizing complex, made up of manganese atoms and a calcium atom."
- 2 (nontechnical usage) a tiny piece of anything wordnet
- 3 A hypothetical particle posited by Greek philosophers as an ultimate and indivisible component of matter.
- 4 (physics and chemistry) the smallest component of an element having the chemical properties of the element wordnet
- 5 The smallest, indivisible constituent part or unit of something.
"Towards the following morning, the thermometer fell to 5°; and at daylight, there was not an atom of water to be seen in any direction."
Show 9 more definitions
- 6 In logical atomism, a fundamental fact that cannot be further broken down.
- 7 The smallest medieval unit of time, equal to fifteen ninety-fourths of a second. historical
- 8 A mote of dust in a sunbeam.
- 9 A very small amount; a whit.
""Doctor, tell me one word more," said Theodore, quivering with suppressed emotion. "How do you think it will end?" / "I have hardly the faintest atom of hope," answered this honest, earnest man."
- 10 An individual number or symbol, as opposed to a list; a scalar value.
- 11 An integer representing a particular string.
- 12 A non-zero member of a partially ordered set that has only zero below it (assuming that the poset has a least element, its "zero").
"In a Venn diagram, an atom is depicted as an area circumscribed by lines but not cut by any line."
- 13 An element of a set that is not itself a set; an urelement.
- 14 An age group division in hockey for nine- to eleven-year-olds. Canada, attributive, usually
Proper Noun
- 1 A Meitei surname from Manipuri
Antonyms
Example
"A water molecule has two hydrogen atoms and one oxygen atom."
Common questions
What is a synonym for "atom"?
Common synonyms include: particle, ace, acid, acidity, agent, air.
How do you use "atom" in a sentence?
A water molecule has two hydrogen atoms and one oxygen atom.
How do you pronounce "atom"?
Pronounced /ˈætəm/.
Etymology
Etymology 1
From Middle English attome, from Middle French athome, from Latin atomus (“smallest particle”), from Ancient Greek ἄτομος (átomos, “indivisible”), from ἀ- (a-, “not”) + τέμνω (témnō, “to cut”, o-grade in τομ-) + -ος (-os). Atoms are so named because they were historically thought up as to be the smallest unit of matter, and thus indivisible. Doublet of atomus.
Etymology 2
From Manipuri ꯑꯇꯣꯝ (ʼatom).