What does "infinitesimal" mean?

A non-zero quantity whose magnitude is smaller than any positive number (by definition it is not a real number).

What is a synonym for "infinitesimal"?

Common synonyms include: microscopic, atomic, corpuscular, diminutive, embryonic, evanescent.

How do you pronounce "infinitesimal"?

Pronounced //ˌɪnfɪnɪˈtɛsɪməl//.

Infinitesimal

//ˌɪnfɪnɪˈtɛsɪməl// adj, noun, slang

adj, noun, slang ·Moderate ·High school level

Definitions

Noun

1
A non-zero quantity whose magnitude is smaller than any positive number (by definition it is not a real number).
2
(mathematics) a variable that has zero as its limit wordnet

Adjective

1
Incalculably, exceedingly, or immeasurably minute; vanishingly small.
"Do you ever get the feeling that you are but an infinitesimal speck, swallowed by the vastness of the universe and beyond?"
2
Of or pertaining to non-zero quantities whose magnitude is less than any positive rational number. not-comparable
3
Very small. informal

Adjective

1
infinitely or immeasurably small wordnet

Synonyms

All synonyms

microscopic atomic corpuscular diminutive embryonic evanescent

Antonyms

All antonyms

enormous infinite infinity

Example

More examples

"It is enough for me to contemplate the mystery of conscious life perpetuating itself through all eternity, to reflect upon the marvelous structure of the universe which we can dimly perceive, and to try humbly to comprehend even an infinitesimal part of the intelligence manifested in nature."

Etymology

From New Latin īnfīnītēsimus + -al. Displaced earlier coordinate term fluxion.

More for "infinitesimal"

Synonyms Sentences Pronunciation Translate

Next best steps

Find stronger synonyms See usage examples Check pronunciation Browse writing guides

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.