infinitesimal

adjective
in·​fin·​i·​tes·​i·​mal | \ (ˌ)in-ˌfi-nə-ˈte-sə-məl How to pronounce infinitesimal (audio) , -zə-məl \

Definition of infinitesimal

 (Entry 1 of 2)

1 : immeasurably or incalculably small an infinitesimal difference
2 : taking on values arbitrarily close to but greater than zero

infinitesimal

noun

Definition of infinitesimal (Entry 2 of 2)

: an infinitesimal quantity or variable

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Other Words from infinitesimal

Adjective

infinitesimally \ (ˌ)in-​ˌfi-​nə-​ˈte-​sə-​mə-​lē How to pronounce infinitesimal (audio) , -​zə-​mə-​ \ adverb

What is the origin of infinitesimal?

Noun

Infinite, as you probably know, means "endless" or "extending indefinitely." It is ultimately from Latin infinitus, the opposite of finitus, 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 1710 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 adjective in a mathematical sense, too, referring to "infinitesimal parts of finite lines." Less than a quarter century later, the adjective had 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 Buffett is far from unique; the documents showed that the amount of money people like Michael Bloomberg, Jeff Bezos or Elon Musk reported to the IRS as income was infinitesimal when measured against their annual gains in wealth. Stephen Engelberg, ProPublica, 11 Oct. 2021 Even a more infinitesimal number of people became sick enough to require hospitalization, 0.003%, or who ultimately died, 0.00035%. Luke Money, Los Angeles Times, 8 July 2021 Almost 2,000 years later, Isaac Newton wanted to understand Kepler’s laws of planetary motion and attempted to find a rigorous way of thinking about infinitesimal change. Kevin Hartnett, Wired, 20 June 2021 Inside was an infinitesimal fragment of the disease that has killed more than 600,000 people in the U.S. and 3.8 million around the world. Nanette Asimov, San Francisco Chronicle, 22 June 2021 While brutal for Bonfire’s early holders, infinitesimal prices are part of the appeal for many hype coin fans. New York Times, 3 Aug. 2021 Almost 2,000 years later, Isaac Newton wanted to understand Kepler’s laws of planetary motion and attempted to find a rigorous way of thinking about infinitesimal change. Kevin Hartnett, Wired, 20 June 2021 Almost 2,000 years later, Isaac Newton wanted to understand Kepler’s laws of planetary motion and attempted to find a rigorous way of thinking about infinitesimal change. Kevin Hartnett, Wired, 20 June 2021 Almost 2,000 years later, Isaac Newton wanted to understand Kepler’s laws of planetary motion and attempted to find a rigorous way of thinking about infinitesimal change. Kevin Hartnett, Wired, 20 June 2021 Recent Examples on the Web: Noun This led to his theory of surreal numbers — a huge new number system containing not only all the real numbers, but also a boggling collection of infinites and infinitesimals, like π minus 1 divided by the cube root of infinity. New York Times, 16 May 2020 Infinities implicitly pervade many familiar mathematical concepts, such as the idea of points as mentioned above, the idea of the continuum, and the concept of infinitesimals in calculus. Quanta Magazine, 16 June 2016

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'infinitesimal.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of infinitesimal

Adjective

1710, in the meaning defined at sense 2

Noun

1706, in the meaning defined above

History and Etymology for infinitesimal

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

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Time Traveler for infinitesimal

Time Traveler

The first known use of infinitesimal was in 1706

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Dictionary Entries Near infinitesimal

infinite series

infinitesimal

infinitesimal calculus

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Last Updated

14 Oct 2021

Cite this Entry

“Infinitesimal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infinitesimal. Accessed 20 Oct. 2021.

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More Definitions for infinitesimal

infinitesimal

adjective

English Language Learners Definition of infinitesimal

: extremely small

infinitesimal

adjective
in·​fin·​i·​tes·​i·​mal | \ in-ˌfi-nə-ˈte-sə-məl How to pronounce infinitesimal (audio) \

Kids Definition of infinitesimal

: extremely small The chance of winning is infinitesimal.

More from Merriam-Webster on infinitesimal

Nglish: Translation of infinitesimal for Spanish Speakers

Britannica.com: Encyclopedia article about infinitesimal

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