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

The view tapers off into infinity.

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 of infinity

• perpetuity
• eternity

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

But overall the topicality is vague, as is the explanation for why this was an eight-episode project (other than that eight sideways is infinity). — Daniel Fienberg, HollywoodReporter, 17 Sep. 2026

The ink included an eye above a small infinity symbol, as well as photos of them having the ink drawn on. — Hannah Sacks, PEOPLE, 17 Sep. 2026

The four thematic worlds included Earth, Water, Light and Sky, ranging from natural pigments and raw textures to fluidity and transparency; shimmer and light shadows, while the sky evoked infinity with voluminous and atmospheric surfaces. — Mayu Saini, Footwear News, 16 Sep. 2026

The new exhibition spans through several rooms before going up an escalator lined with mirrors to reach the infinity room installation one floor up. — ABC News, 9 Sep. 2026

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

Rhymes for infinity

• affinity
• divinity
• salinity
• vicinity
• virginity
• alkalinity
• consanguinity
• crystallinity
• femininity
• masculinity

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