infinity

noun

in·​fin·​i·​ty in-ˈfi-nə-tē 

plural infinities

1

a

: 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

3

a

: 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

Synonyms

• eternity
• everlasting
• foreverness
• perpetuity

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.

Recent Examples on the Web

Days here are ten hours, whereas days in the U.S. can just stretch into infinity. —Rachel Syme, The New Yorker, 9 July 2024

Theoretical predictions for its value were unhelpful, covering the entire span from zero to infinity. —Stanley J. Brodsky, Scientific American, 16 Apr. 2024

Happy anniversary to CeCe and Alvin, and cheers to another 40 years of love and joy–times infinity! —Elizabeth Ayoola, Essence, 27 June 2024

But this infinity, referred to as the Landau pole after physicist Lev Landau, reveals only that the computational method has failed rather than telling us about the strong force. —Stanley J. Brodsky, Scientific American, 16 Apr. 2024

Word History

Etymology

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

First Known Use

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

Phrases Containing infinity

• infinity pool
• infinity scarf

Kids Definition

infinity

noun

in·​fin·​i·​ty in-ˈfin-ət-ē 

plural infinities

1

a

: the quality of being infinite

b

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

2

: an indefinitely great number or amount

3

: a point infinitely far away

Etymology

Middle English infinite "the quality of having no limit," from early French infinité (same meaning), derived from Latin infinitus (adjective) "having no limit," from in- "not" and finitus, past participle of finire "to limit, bring to an end," from finis "end, limit" — related to define, final, finish