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

"We classify everybody on board as what we call a high-risk contact," WHO's epidemic and pandemic preparedness and prevention director Maria Van Kerkhove said Saturday.

From Barron's • May 10, 2026

The initiative, funded by Uber, Lyft, DoorDash and other businesses, allowed gig companies to classify their workers as contractors rather than employees.

From Los Angeles Times • Apr. 30, 2026

Justice Samuel Alito’s majority opinion recognizes that the Constitution “almost never permits a State to discriminate on the basis of race” and reaffirms that “strict scrutiny” applies whenever governments intentionally classify citizens by race.

From The Wall Street Journal • Apr. 29, 2026

Researchers classify Vasuki indicus within the madtsoiidae family, a group of snakes that existed for nearly 100 million years, from the Late Cretaceous to the Late Pleistocene.

From Science Daily • Apr. 29, 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

Related Words

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