classify

American  

[klas-uh-fahy] / ˈklæs əˌfaɪ /

verb (used with object)

• classifies,
  present (3rd person singular)
• classified,
  past participle,  past
• classifying
  present participle

1. to arrange or organize by classes; order according to class.

   Synonyms:

   group, categorize, rate, rank, class

2. to assign a classification to (information, a document, etc.).

3. to limit the availability of (information, a document, etc.) to authorized persons.

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classify British  

/ ˈklæsɪˌfaɪ /

verb

1. to arrange or order by classes; categorize

2. government to declare (information, documents, etc) of possible aid to an enemy and therefore not available to people outside a restricted group

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Other Word Forms

Derived Forms

• classifier
  noun
• unclassifiableness
  noun
• misclassify
  verb (used with object)
• overclassify
  verb (used with object)
• preclassify
  verb (used with object)
• classifiable
  adjective
• nonclassifiable
  adjective
• unclassifiable
  adjective
• unclassifying
  adjective
• unclassifiably
  adverb

Inflected Forms

Participles

• classifying
  present
• classified
  past

Conjugated Forms

Present

• classify
  simple
• classifies
  simple
• have classified
  perfect
• has classified
  perfect
• am classifying
  progressive
• are classifying
  progressive
• is classifying
  progressive
• have been classifying
  perfect progressive
• has been classifying
  perfect progressive

Past

• classified
  simple
• had classified
  perfect
• was classifying
  progressive
• were classifying
  progressive
• had been classifying
  perfect progressive

Future

• will classify
  simple
• will have classified
  perfect
• will be classifying
  progressive
• will have been classifying
  perfect progressive

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Etymology

Origin of classify

First recorded in 1790–1800; from Latin classi(s) class + -fy

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Explanation

Humans seem to have the need to classify things, arranging them into different classes by such unifying traits as size, color, or shape. It’s fine to do this to inanimate objects, but doing it to people can be very wrong. The word classify contains the base word class, which means "category" and comes from the Latin classis, which actually referred to an army or group called to arms. It eventually came to mean "a group," and thus classify means "to group." As a security measure, you can also classify information that is not to be shared. Writer Ambrose Bierce once said, “The small part of ignorance that we arrange and classify we give the name of knowledge.”

Example Sentences

See Examples For:

classify classifies classified classifying

They say they are investigating his failure to hand over his passports, but this does not classify him as a fugitive.

From Barron's ● Oct. 28, 2026

Its genetic makeup and physical features were so distinctive that researchers created an entirely new family to classify it.

From Science Daily ● Oct. 8, 2026

Instead, it uses machine learning to classify inputs to a set of predetermined outputs: “yes” or “no,” a numerical score, or answers on a list.

From The Wall Street Journal ● Oct. 2, 2026

Meanwhile the US State Department continues to classify travel to China as a Level 2 advisory urging travellers to "exercise increased caution" because of the risk of arbitrary law enforcement, exit bans and detention.

From BBC ● Sep. 28, 2026

Then yesterday in my science elective, we were doing this cool mystery-powder investigation where we had to classify a substance as an acid or a base.

From "Wonder" by R. J. Palacio

They developed the Nova system, which classifies the degree to which a food product is processed, from minimal to ultraprocessed.

From Los Angeles Times ● Sep. 29, 2026

The International Agency for Research on Cancer classifies the chemical as a probable carcinogen and has linked exposure to bladder cancer, multiple myeloma and non-Hodgkin lymphoma.

From Science Daily ● Sep. 7, 2026

The United States for years refused contact with Hamas, which it classifies as a terrorist organisation and which led the October 7, 2023 attack on Israel that sparked the Gaza war.

From Barron's ● Aug. 16, 2026

Sunscreen is regulated as a cosmetic in Europe, leading to more variety than in the U.S., which classifies it as an over-the-counter drug.

From The Wall Street Journal ● Aug. 14, 2026

In Plato’s allegory of the metals, the philosopher classifies men into groups of gold, silver, and lead.

From "Long Walk to Freedom" by Nelson Mandela

Inulin is classified as a prebiotic because it nourishes certain beneficial gut bacteria rather than directly supplying living microorganisms, as probiotics do.

From Science Daily ● Oct. 28, 2026

The "Dueling Dinosaurs" discovery became crucial to the research published by Lindsay Zanno and James Napoli that classified Nanotyrannus as separate from T. rex.

From BBC ● Oct. 27, 2026

Campaign ad transcripts were classified as positive, negative, unclear,

From The Wall Street Journal ● Oct. 23, 2026

In a 1975 classified ad in the L.A.

From Los Angeles Times ● Oct. 23, 2026

But trusting him with the classified details of my heart turned out to be a rookie mistake.

From "Americanized" by Sara Saedi

Of course, analysts aren’t focusing on statistics when classifying every rally as from Santa Claus, but instead are engaged in sales and marketing.

From MarketWatch ● Oct. 26, 2026

These findings suggest that the nutritional characteristics of individual foods may be more informative than simply classifying everything as ultra-processed.

From Science Daily ● Oct. 21, 2026

The CDC has not yet included the Pennsylvania deaths in its national tally while it reviews the records and develops standardized criteria for classifying measles deaths.

From Salon ● Sep. 6, 2026

"It is therefore highly probable that we will end up classifying it as a megafire."

From Barron's ● Aug. 3, 2026

In fact, mathematicians started analyzing and classifying the points where a function blows up: singularities.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

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