phenomenon

noun

phe·​nom·​e·​non fi-ˈnä-mə-ˌnän 

-nən

plural phenomena fi-ˈnä-mə-nə 

-ˌnä

or phenomenons

1

plural phenomena : an observable fact or event : an item of experience or reality

weather phenomena

… the cultural phenomenon of America going to the movies …

—Lucius Shepard

But there are always anomalies, phenomena that the paradigm cannot account for …

—John Horgan

2

a

plural phenomenons : someone or something that is very popular or impressive especially because of an unusual quality or ability

the greatest literary phenomenon of the decade

… why reality TV became a phenomenon in the first place: it's expressive, which is what pop culture is supposed to be.

—Tom Carson

In tornado country … storm chasing has become a phenomenon.

—Priit J. Vesilind

b

: a rare or significant fact or event

… one of a number of optical phenomena in the sky that depend on light rays interacting with ice or water in the atmosphere …

—C. Claiborne Ray

3

plural phenomena

a

philosophy : an object or aspect known through the senses rather than by thought or intuition

b

: a fact or event of scientific interest warranting scientific description and explanation

quantum phenomena

… phenomena ranging from Earth's magnetic field to the planet's energy balance.

—Ray Ladbury

This natural phenomenon was named the greenhouse effect because it was once thought that greenhouses were heated in a similar manner.

—Frederick J. Lutgens and Edward J. Tarbuck

Can phenomena be used as a singular?: Usage Guide

Phenomena has been in occasional use as a singular since the early 18th century, as has the plural phenomenas. Our evidence shows that singular phenomena is primarily a speech form used by poets, critics, and professors, among others, but one that sometimes turns up in edited prose.

Although it seemed like a fad a few years ago, Twitter has evolved into a phenomena with more than 200 million users …

—Myron P. Medcalf

It is etymologically no more irregular than stamina and agenda, but it has nowhere near the frequency of use that they have, and while they are standard, phenomena is still rather borderline.

Synonyms of phenomenon

• miracle
• wonder
• marvel

Examples of phenomenon in a Sentence

For example, we talk more loudly in cars, because of a phenomenon known as the Lombard effect—the speaker involuntarily raises his voice to compensate for background noise. —John Seabrook, New Yorker, 23 June 2008

This follow-the-winemaker phenomenon is a unique wrinkle in our wine culture. —James Laube, Wine Spectator, 15 May 2008

The days and nights of the Irish pub, smoky and dark and intimate, are giving way to another phenomenon: the superpub. These are immense places, loud with music; part honkytonk, part dance hall, some servicing as many as a thousand drinkers on several floors. —Pete Hamill, Gourmet, April 2007

They were ephemera and phenomena on the face of a contemporary scene. That is, there was really no place for them in the culture, in the economy, yet they were there, at that time, and everyone knew that they wouldn't last very long, which they didn't. —William Faulkner, letter, 7 Mar. 1957

natural phenomena like lightning and earthquakes

the greatest literary phenomenon of the decade

The movie eventually became a cultural phenomenon.

Recent Examples on the Web

One alternate ending in particular puts the phenomenon in a different light. —JSTOR Daily, 5 Nov. 2025

Wang highlighted regional developments including France’s cultural assets combined with new technology, South Korea’s global Hallyu phenomenon, Japan’s strength in animation and manga adaptation, and Singapore’s commercial integration model. —Naman Ramachandran, Variety, 4 Nov. 2025

Once popular mainly in Asia, K-pop music has become a global phenomenon. —Eunice Yoon, CNBC, 4 Nov. 2025

Here’s what to know about this special phenomenon. —Chantelle Lee, Time, 4 Nov. 2025

Word History

Etymology

Late Latin phaenomenon, from Greek phainomenon, from neuter of phainomenos, present participle of phainesthai to appear, middle voice of phainein to show — more at fancy

First Known Use

1583, in the meaning defined at sense 1

Phrases Containing phenomenon

• phi phenomenon
• unidentified aerial phenomenon
• unidentified anomalous phenomenon

Rhymes for phenomenon

• agamemnon
• automaton
• diencephalon
• panopticon
• aileron
• antiphon
• autobahn
• carillon
• castellan
• celadon
• cephalon
• chitosan

Kids Definition

phenomenon

noun

phe·​nom·​e·​non fi-ˈnäm-ə-ˌnän 

-nən

plural phenomena -nə 

-ˌnä

or phenomenons

1

plural phenomena : an observable fact or event

2

: a fact, feature, or event of scientific interest

3

a

: a rare or important fact or event

b

plural phenomenons : an exceptional, unusual, or abnormal person or thing

Medical Definition

phenomenon

noun

phe·​nom·​e·​non fi-ˈnäm-ə-ˌnän, -nən 

plural phenomena -nə, -ˌnä 

1

: an observable fact or event

2

a

: an object or aspect known through the senses rather than by thought or intuition

b

: a fact or event of scientific interest susceptible of scientific description and explanation