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

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Derived Forms

Inflected Forms

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Conjugated Forms

Present

Past

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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.

The House advanced a version of a bill that has already cleared the Senate, seeking to improve recycling data collection and define recycling at a national level.

From Barron's • Jun. 17, 2026

To define the contours of that right, courts will look to history and tradition, just as Justice Samuel Alito did in Dobbs.

From Slate • Jun. 16, 2026

Ten years on, Orlando’s Pulse remains both a physical absence and an emotional presence — one that continues to define survivors’ lives long after the headlines have faded.

From Salon • Jun. 13, 2026

Asked where he now sits on a spectrum between Cameron-era conservatism and Trump-era populism, Hilton rejected the framing, arguing that both were political movements that did not define him "personally".

From BBC • Jun. 12, 2026

If permitted to define a decade somewhat loosely, then the next decade was the most crucial and consequential in American history.

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