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

• 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

The 8,000-square-foot property boasts extensive outdoor space, with an infinity swimming pool and a lounge area outfitted with a fireplace. —India Roby, Architectural Digest, 16 Sep. 2025

This destination will offer the island’s only rooftop infinity-edge pool with panoramic views, a rooftop oasis with indoor-outdoor dining and private cabanas, two resort-style pools, a fitness center with saunas, a library, meeting rooms, concierge and valet. —Roger Sands, Forbes.com, 15 Sep. 2025

The kitchen is great for entertaining with an easy flow out to the alfresco dining and lounging areas alongside the infinity-edge pool, all with unobstructed views of the horizon. —Demetrius Simms, Robb Report, 15 Sep. 2025

Another secret drinking lair within the Cosmopolitan, Ghost Donkey offers delicious drinks, pulsating Christmas lights and mirrors that give off infinity room vibes. —Tim McGovern, PEOPLE, 11 Sep. 2025

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