in·​fin·​i·​ty | \in-ˈfi-nə-tē \
plural infinities

Definition of infinity 

1a : the quality of being infinite

b : unlimited extent of time, space, or quantity : boundlessness

2 : an indefinitely great number or amount an infinity of stars

3a : the limit of the value of a function or variable when it tends to become numerically larger than any preassigned finite number

b : a part of a geometric magnitude that lies beyond any part whose distance from a given reference position is finite do parallel lines ever meet if they extend to infinity

c : a transfinite number (such as aleph-null)

4 : a distance so great that the rays of light from a point source at that distance may be regarded as parallel

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Examples of infinity in a Sentence

The view tapers off into infinity. a series of numbers that continues to infinity The night sky was filled with an infinity of stars.
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Recent Examples on the Web

Quality time with big philosophical questions and conundrums, including the nature of infinity, what Heisenberg really meant and the Monty Hall Problem. Jim Higgins, Milwaukee Journal Sentinel, "85 books for summer reading," 18 May 2018 The silky double-layer polyester infinity scarf is fitted with a big food-grade silicon teething ring that could pass, sans child, as a clunky accent piece. Judi Dash,, "Fashionable, versatile and safe: what every traveler needs," 26 Mar. 2018 This week’s photos take us out to our solar system and then to infinity and beyond—almost. Shannon Stirone, WIRED, "Space Photos of the Week: Mars Has Spiders in the Springtime," 14 July 2018 Zero also helps us understand its antithesis, infinity, in all of its extreme weirdness. Brian Resnick, Vox, "The mind-bendy weirdness of the number zero, explained," 5 July 2018 And unlike the standard theory of gravity, string theory can describe its interactions mathematically without getting strange infinities. Lorenzo Bianchi, Newsweek, "Was This Stephen Hawking's Theory of Everything?," 19 Mar. 2018 Leave all the camera settings the same for this shot but dial the manual focus several feet closer than infinity. Emily Price, Popular Mechanics, "How to Capture Perfect Fireworks Photos," 3 July 2018 There is also an infinity saltwater pool overlooking the ocean and an outdoor pizza oven. Candace Taylor, WSJ, "Relisted Newport Estate Seeks to be Rhode Island’s Priciest Home," 28 June 2018 The guy next to me, who has a Sputnik tattoo on one forearm and an infinity symbol inked on the other, writes something in his notebook. Sarah Scoles, WIRED, "Why Darpa Wants Everyone to Launch Tiny Satellites," 30 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'infinity.' 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 infinity

14th century, in the meaning defined at sense 1a

History and Etymology for infinity

Middle English infinite, borrowed from Anglo-French infinité, borrowed from Latin infīnitāt-, infīnitās, from in- in- entry 1 + fīnis "boundary, limit, terminal point, ending" + -itāt-, -itās -ity — more at final entry 1

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Learn More about infinity

Statistics for infinity

Last Updated

11 Oct 2018

Look-up Popularity

Time Traveler for infinity

The first known use of infinity was in the 14th century

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More Definitions for infinity



English Language Learners Definition of infinity

: the quality of having no limits or end : the quality of being infinite

: a space, amount, or period of time that has no limits or end

: a very great number or amount


in·​fin·​i·​ty | \in-ˈfi-nə-tē \
plural infinities

Kids Definition of infinity

1 : the quality of being without limits the infinity of space

2 : a space, quantity, or period of time that is without limit

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Comments on infinity

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