Synonyms

define

American

[dih-fahyn] / dɪˈfaɪn /

verb (used with object)

to state or set forth the meaning of (a word, phrase, etc.).

They disagreed on how to define “liberal.”
to explain or identify the nature or essential qualities of; describe.

to define judicial functions.
to fix or lay down clearly and definitely; specify distinctly.

to define one's responsibilities.

Synonyms:

enumerate, detail, describe, name, state
to determine or fix the boundaries or extent of.

to define property with stakes.
to make clear the outline or form of.

The roof was boldly defined against the sky.

verb (used without object)

to set forth the meaning of a word, phrase, etc.; construct a definition.

define British

/ dɪˈfaɪn /

verb

to state precisely the meaning of (words, terms, etc)
to describe the nature, properties, or essential qualities of
to determine the boundary or extent of
(often passive) to delineate the form or outline of

the shape of the tree was clearly defined by the light behind it
to fix with precision; specify

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future

Etymology

Origin of define

First recorded in 1325–75; Middle English def(f)inen, from Anglo-French, Old French definer “to put an end to,” from Latin dēfīnīre ”to limit, define,“ equivalent to dē- “from, away from, out of” + fīnīre “to end”; see origin at de-, finish

Explanation

If you can't define a word, turn to the dictionary. That's always the best way to learn the definition. Likewise, anything you can describe completely is something you can define. The early French and Latin roots of the verb mean something closer to "to limit" or "to create a boundary," but this is really what we do when we define something: we limit its meaning to something specific. So when you're thinking about the word define, remember that you're looking to create a boundary of meaning around it, whether you're specifying the meaning of a word or a larger concept. To define a word such as astronomy is to define both the word and the realm of science that it's concerned with.

Keep Reading on Vocabulary.com

Vocabulary lists containing define

The Language of Standardized Tests, List 1

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Jim Burke's Academic Vocabulary List

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The ACT: The Language of the Test, List 1

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

define defines defined defining

Both men deny intentionally ever taking performance-enhancing drugs, but away from that issue their showdown is wrapped in the contradictions that define modern boxing.

From BBC ● Sep. 11, 2026

The industrial mechanic and former union leader is a relative political novice, and says he's always refused to define himself along party lines.

From Barron's ● Sep. 11, 2026

When they do set priorities, he said, they often fail to drill down far enough; they don’t set meaningful deadlines and define what success looks or feels like.

From The Wall Street Journal ● Sep. 10, 2026

You could, if you wanted to, define that as an act of war.

From Salon ● Sep. 7, 2026

The term sex refers to the biological and physiological characteristics that define men and women, while gender refers to society’s constructed roles, expectations, behaviors, attitudes, and activities that it deems appropriate for men and women.

From "Music and the Child" by Natalie Sarrazin

The work by Oxford University, which is published in the International Journal of Cancer, defines any drink at 65 degrees Celsuis or above as "very hot" and posing a potential risk.

From BBC ● Sep. 8, 2026

“Phil Jackson defines championship basketball for a reason,” Lakers governor Jeanie Buss said in a statement released by the team.

From Los Angeles Times ● Sep. 8, 2026

There’s Mênis, which Nora defines as the anger of a society or a people.

From Salon ● Sep. 3, 2026

MSCI, for instance, defines “world” as developed markets only, so without including emerging markets to counterbalance some of the U.S. stock influence, the percentage overlap with the S&P 500 rises.

From The Wall Street Journal ● Sep. 3, 2026

I am not a philosopher, but I believe that Oskar Schindler defines heroism.

From "The Boy on the Wooden Box" by Leon Leyson

Added Harvey Mason Jr., the academy’s CEO: “Not only has their music defined generations, but they’ve been equally exemplary in their dedication to humanitarian work and using their platform for good.”

From Los Angeles Times ● Sep. 10, 2026

The June to August season was defined by severe, back-to-back heatwaves that shut schools, dried up rivers and primed the land for devastating wildfires.

From Barron's ● Sep. 10, 2026

After the UN defined the current El Niño as supersized, the Farmers’ Almanac predicts this upcoming winter will look very different.

From The Wall Street Journal ● Sep. 8, 2026

“Behind its gates lies a property defined by serenity and intention,” the description read.

From MarketWatch ● Sep. 8, 2026

The edges of the cloud are crisp and defined.

From "Shouting at the Rain" by Lynda Mullaly Hunt

Toreno Winn, stylist, photographer and creative director, is drawn to the experimental qualities of CDG, Junya Watanabe and Sacai, with playful proportions and unexpected silhouettes defining his collection.

From Los Angeles Times ● Sep. 11, 2026

Its defining achievement is ordered liberty: suspicion of ideological conceit, faith in common decency, respect for tradition and a preference for gradual change.

From The Wall Street Journal ● Sep. 10, 2026

"But now it's about Ternus defining the AI chapter."

From Barron's ● Aug. 31, 2026

Entanglement is one of the defining phenomena of quantum physics.

From Science Daily ● Aug. 31, 2026

This was the defining moment in the correspondence.

From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023