dictionary

American  

[dik-shuh-ner-ee] / ˈdɪk ʃəˌnɛr i /

noun

• dictionaries
  plural

1. 

   a book or digital resource (such as Dictionary.com) containing a selection of words and information about their meanings, pronunciations, etymologies, inflected forms, derived forms, etc., in either the same or another language; lexicon; glossary.

   an unabridged dictionary of English;

   a Japanese–English dictionary.

2. a book or digital resource giving information on a particular subject or on a particular class of words, names, or facts, usually arranged alphabetically.

   a biographical dictionary;

   a dictionary of mathematics.

3. Computers.

   1. a list of codes, terms, keys, etc., and their meanings, used by a computer program or system.

   2. a selection of words used by a piece of software, such as a word-processing program, to check the spelling of text entered.

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dictionary British  

/ ˈdɪkʃənərɪ, -ʃənrɪ /

noun

1. 1. a reference resource, in printed or electronic form, that consists of an alphabetical list of words with their meanings and parts of speech, and often a guide to accepted pronunciation and syllabification, irregular inflections of words, derived words of different parts of speech, and etymologies

   2. a similar reference work giving equivalent words in two or more languages. Such dictionaries often consist of two or more parts, in each of which the alphabetical list is given in a different language

      a German-English dictionary

   3. ( as modifier ) See also glossary lexicon thesaurus

      a dictionary definition

2. a reference publication listing words or terms of a particular subject or activity, giving information about their meanings and other attributes

   a dictionary of gardening

3. a collection of information or examples with the entries alphabetically arranged

   a dictionary of quotations

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Other Word Forms

Noun Inflected Forms

• dictionaries
  plural

Etymology

Origin of dictionary

First recorded in 1570–80; from Medieval Latin dictiōnārium, dictiōnārius, from Late Latin dictiōn- stem of dictiō “word” + -ārium, -ārius adjective and noun suffix; see diction ( def. ), -ary ( def. )

Explanation

A dictionary is a collection of words and their definitions (and sometimes other information). Such collections are usually printed as books, but some are now designed for use on computers. Dictionary originally came from the Latin word dictionarius, meaning "a manual or book of words." A dictionary is most commonly used to look up the definitions of particular words, but other information, such as etymology and usage guidelines, often appears as well. Electronic dictionaries can include even more information, like slang and popular texting acronyms, such as "ttyn," which stands for "talk to you never."

Example Sentences

See Examples For:

dictionary dictionaries

Similarly, in Sweden a new word for "hymen" was added in the academic dictionary after a 2009 campaign.

From BBC ● Sep. 23, 2026

Chief among them is the practice of naming each newborn by pointing to arandom word in the family dictionary.

From The Wall Street Journal ● Sep. 2, 2026

McMahon relied on dictionary definitions, one of which describes DEI as “the idea that people have equal rights and treatment and be welcomed and included.”

From Slate ● May 14, 2026

If you’re chronically online like me, you’ve probably come across a slang-suffix that’s become part of the lexicon despite not being formally added to a dictionary — yet.

From Salon ● May 7, 2026

“That’s where you can always find a dictionary of standard English in a library.”

From "Mr. Lemoncello's Library Olympics" by Chris Grabenstein

For his part, Thomas writes as though history resides principally in legal texts, 19th-century dictionaries, and carefully parsed debates over sovereignty.

From Slate ● Jul. 2, 2026

Middle age enrichment included income level at age 40, access to resources such as magazine subscriptions, dictionaries, and library cards, and how often participants visited places like museums or libraries.

From Science Daily ● Apr. 15, 2026

The four books, which were immediately withdrawn from sale, are subject to a recall procedure and will be destroyed, Hachette said, promising a "thorough review of its textbooks, educational materials and dictionaries".

From Barron's ● Jan. 16, 2026

Simply by dint of their tablet-like heft, dictionaries make a claim for longevity and authority.

From The Wall Street Journal ● Dec. 19, 2025

Most standard music dictionaries and encyclopedias also focus almost exclusively on Western Classical music.

From "Understanding Basic Music Theory" by Catherine Schmidt-Jones and Russel Jones

Related Words

• glossary
• language
• vocabulary