infinitesimal

1 of 2

adjective

in·​fin·​i·​tes·​i·​mal (ˌ)in-ˌfi-nə-ˈte-sə-məl How to pronounce infinitesimal (audio)
-zə-məl
1
: immeasurably or incalculably small
an infinitesimal difference
2
: taking on values arbitrarily close to but greater than zero
infinitesimally adverb

infinitesimal

2 of 2

noun

: an infinitesimal quantity or variable

Did you know?

What is the origin of infinitesimal?

Infinite, as you probably know, means "endless" or "extending indefinitely." It is ultimately from Latin infīnītus, the opposite of fīnītus, meaning "finite." The notion of smallness in infinitesimal derives from the mathematical concept that a quantity can be divided endlessly; no matter how small, it can be subdivided into yet smaller fractions, or infinitesimals. The concept was still in its infancy in the early 1700s when Irish philosopher George Berkeley observed that some people "assert there are infinitesimals of infinitesimals of infinitesimals, etc., without ever coming to an end." He used the word in a mathematical sense, too, referring to "infinitesimal parts of finite lines." Later, the adjectival form acquired a general sense applicable to anything too small to be measured.

Examples of infinitesimal in a Sentence

Adjective an infinitesimal moment in time a soft drink with only an infinitesimal amount of caffeine
Recent Examples on the Web
Adjective
No, the expedition hadn’t deployed underwater video, and the chances would have been infinitesimal anyway. Cullen Murphy, The Atlantic, 11 Oct. 2024 The movie’s physicality, at its most vital, is infinitesimal. Richard Brody, The New Yorker, 13 Sep. 2024
Noun
Does something smaller exist? Particle physicists use gigantic accelerators to investigate the infinitesimal. Big Think, 24 June 2024 Initially, Newton and Leibniz came up with objects called infinitesimals. Jordana Cepelewicz, Quanta Magazine, 31 Aug. 2023 See all Example Sentences for infinitesimal 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'infinitesimal.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Adjective

borrowed from New Latin infīnītēsimālis, from infīnītēsimus "infinite in rank" (from Latin infīnītus "having no limit, infinite entry 1" + -ēsimus, suffix of higher ordinal numbers) + Latin -ālis -al entry 1 — more at vigesimal

Noun

New Latin infīnītēsimus "infinite in rank" + -al entry 2 — more at infinitesimal entry 1

First Known Use

Adjective

1710, in the meaning defined at sense 2

Noun

1706, in the meaning defined above

Time Traveler
The first known use of infinitesimal was in 1706

Podcast

Dictionary Entries Near infinitesimal

Cite this Entry

“Infinitesimal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infinitesimal. Accessed 31 Oct. 2024.

Kids Definition

infinitesimal

adjective
in·​fin·​i·​tes·​i·​mal
(ˌ)in-ˌfin-ə-ˈtes-ə-məl
: too small to be measurable
infinitesimally
-mə-lē
adverb

More from Merriam-Webster on infinitesimal

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!