classify

American  

[klas-uh-fahy] / ˈklæs əˌfaɪ /

verb (used with object)

classified, classifying

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

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

Etymology

Origin of classify

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

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

Participants answered three questions that were used to classify their loneliness as low, average or high.

From Science Daily • Apr. 14, 2026

“We classify indicators as trend-following or momentum gauges, overbought and oversold metrics, and relative strength inputs,” she said.

From Barron's • Apr. 10, 2026

The latest insider ratio would need to be even higher before the Seyhuns would classify it as solidly bullish.

From MarketWatch • Apr. 6, 2026

AI was used to classify federal charging documents, including identifying which cases referenced video evidence; those classifications were reviewed by reporters for accuracy.

From The Wall Street Journal • Mar. 8, 2026

“But necessary to learn and classify all the Underworld plants. We will be working on these in November.”

From "The Marvellers" by Dhonielle Clayton

Related Words

• allocate
• analyze
• arrange
• distribute
• divide
• label
• organize
• segregate