infinitesimal

American  

[in-fin-i-tes-uh-muhl] / ˌɪn fɪn ɪˈtɛs ə məl /

adjective

1. exceedingly small; minute.

   Capillaries, the infinitesimal vessels in our circulatory system, are small enough that red blood cells must flow through them single-file.

2. Mathematics.

   1. immeasurably small; less than an assignable quantity.

      An infinitesimal number is never zero, but it comes pretty close.

   2. of, relating to, or involving variables having zero as a limit.

      infinitesimal calculus.

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noun

1. an infinitesimal quantity.

2. Mathematics. a variable having zero as a limit.

infinitesimal British  

/ ˌɪnfɪnɪˈtɛsɪməl /

adjective

1. infinitely or immeasurably small

2. maths of, relating to, or involving a small change in the value of a variable that approaches zero as a limit

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noun

1. maths an infinitesimal quantity

infinitesimal Scientific  

/ ĭn′fĭn-ĭ-tĕs′ə-məl /

1. Capable of having values approaching zero as a limit.

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1. A function or variable continuously approaching zero as a limit.

Other Word Forms

• infinitesimality noun
• infinitesimally adverb
• infinitesimalness noun

Etymology

Origin of infinitesimal

First recorded in 1645–55; from New Latin infīnītēsim(us), equivalent to Latin infīnīt(us) infinite + -ēsimus suffix of ordinal numerals + -al ¹

Example Sentences

Father, his jeweler’s glass in his eye, was bent over the shoulder of the newest apprentice, deftly selecting an infinitesimal part from the array before them on the workbench.

From Literature

But Jonah could make out one line, a title at the top of an infinitesimally small list.

From Literature

He had not gone far when the ground began, infinitesimally at first but then quite unmistakably, to shake under his feet.

From Literature

But a car either complies or it does not, no matter how infinitesimal the infraction.

From BBC

“The chance that a kid will get a concept in front of the inventor relations person and that the inventor relations person says yes is minuscule, tiny, infinitesimal.”

From The Wall Street Journal

Related Words

• imperceptible
• insignificant
• microscopic
• minuscule
• negligible