# infinitesimal

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

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 There are still people whose traces on Google are infinitesimal or nonexistent, and a good many things remain insufficiently archived. Its allure lies in its recognition that the most infinitesimal changes at the outset can lead almost identical systems into drastically differing directions over time. Its allure lies in its recognition that the most infinitesimal changes at the outset can lead almost identical systems into drastically differing directions over time. The cost of storage is infinitesimal compared to the costs of not having these supplies on hand, and a well-functioning government would have recognized this and planned accordingly. Since such craft have no more than an infinitesimal chance of being found, radio broadcasts from Earth, travelling at the speed of light, are more likely to make contact. The board will handle an infinitesimal slice of those, maybe 25 or 30 in its first year—and Facebook is obliged to respect its decisions only in those individual cases. Think of the World Wide Web, the power grid and the universe, of which the Milky Way is an infinitesimal node in a seemingly boundless network of galaxies. The margin separating one winner from the next is often infinitesimal. Recent Examples on the Web: Noun 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.

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.

## First Known Use of infinitesimal

1710, in the meaning defined at sense 2

Noun

1706, in the meaning defined above

## History and Etymology for infinitesimal

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

## The first known use of infinitesimal was in 1706

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infinitesimality

## Statistics for infinitesimal

Last Updated

4 May 2020

Cite this Entry

“Infinitesimal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infinitesimal. Accessed 26 May. 2020.

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More Definitions for infinitesimal

infinitesimal

## English Language Learners Definition of infinitesimal

: extremely small

infinitesimal

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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More from Merriam-Webster on infinitesimal

Spanish Central: Translation of infinitesimal

What made you want to look up infinitesimal? Please tell us where you read or heard it (including the quote, if possible).

#### homonymous

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