[ dik-shuh-ner-ee ]
/ ˈdɪk ʃəˌnɛr i /
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noun, plural dic·tion·ar·ies.
a book, optical disc, mobile device, or online lexical resource (such as Dictionary.com) containing a selection of the words of a language, giving information about their meanings, pronunciations, etymologies, inflected forms, derived forms, etc., expressed in either the same or another language; lexicon; glossary. Print dictionaries of various sizes, ranging from small pocket dictionaries to multivolume books, usually sort entries alphabetically, as do typical CD or DVD dictionary applications, allowing one to browse through the terms in sequence. All electronic dictionaries, whether online or installed on a device, can provide immediate, direct access to a search term, its meanings, and ancillary information: an unabridged dictionary of English; a Japanese-English dictionary.
a book giving information on particular subjects or on a particular class of words, names, or facts, usually arranged alphabetically: a biographical dictionary; a dictionary of mathematics.
  1. a list of codes, terms, keys, etc., and their meanings, used by a computer program or system.
  2. a list of words used by a word-processing program as the standard against which to check the spelling of text entered.
Should you take this quiz on “shall” versus “should”? It should prove to be a quick challenge!
Question 1 of 6
Which form is used to state an obligation or duty someone has?

Origin of dictionary

1520–30; <Medieval Latin dictiōnārium,dictiōnārius<Late Latin dictiōn- word (see diction) + -ārium, -ārius-ary
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use dictionary in a sentence

British Dictionary definitions for dictionary

/ (ˈdɪkʃənərɪ, -ʃənrɪ) /

noun plural -aries
  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 languagea German-English dictionary
  3. (as modifier)a dictionary definition See also glossary, lexicon, thesaurus
a reference publication listing words or terms of a particular subject or activity, giving information about their meanings and other attributesa dictionary of gardening
a collection of information or examples with the entries alphabetically arrangeda dictionary of quotations

Word Origin for dictionary

C16: from Medieval Latin dictiōnārium collection of words, from Late Latin dictiō word; see diction
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