infinitesimal

adjective
in·​fin·​i·​tes·​i·​mal | \(ˌ)in-ˌfi-nə-ˈte-sə-məl, -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 , -​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

And the marginal cost of overpaying is infinitesimal relative to that base. Peter Kafka, Recode, "Here’s what HBO’s new boss really said about the company’s plans under AT&T," 10 July 2018 Assuming Boogie keeps his ego in check—and the Warriors’ culture seems to do a good job of that—the margin of error for this team went from small to infinitesimal. Rohan Nadkarni, SI.com, "The Case For LeBron to Back Out of His Deal With the Lakers," 3 July 2018 For the masses of aspiring players, whose chances of succeeding are infinitesimal, the costs are human and in many cases quite brutal. Laurent Dubois, The Atlantic, "How Not to Scout for Soccer Talent," 14 June 2018 After all, as others have pointed out, dockless bike graveyards are infinitesimal compared to their motor-vehicle counterparts. Eben Weiss, Outside Online, "Bike Share Can Save Our Cities—If We Let It," 13 June 2018 In fact, the film industry, despite its very high cultural profile, is an almost infinitesimal factor in the states $2.6 trillion economy, and not even very important in Southern California. San Francisco Chronicle, "One welfare boost for the poor, another for the rich," 11 June 2018 According to the Red Cross Society of China, the world’s most populous nation is home to roughly 8 million people of short stature—meaning that the Kingdom only houses an infinitesimal proportion. Charlie Campbell / Kunming, Time, "Finding Love in the Kingdom of the Little People," 1 June 2018 The negative health effects of DEET have been shown to be infinitesimal over billions of uses and a human lifetime of use. Wes Siler, Outside Online, "Is DEET Safe?," 18 May 2018 Two parallel lines, forever side by side yet forever apart - The space between them infinitesimalyet infinite. Cristela Guerra, BostonGlobe.com, "Cambridge to imprint more sidewalk poetry this fall," 15 May 2018

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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The first known use of infinitesimal was in 1706

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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 \

Kids Definition of infinitesimal

: extremely small The chance of winning is infinitesimal.

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