[ dik-shuh-ner-ee ]
See synonyms for dictionary on Thesaurus.com
noun,plural dic·tion·ar·ies.
  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.

  1. Computers.

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

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

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, -ary

Words Nearby dictionary

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use dictionary in a sentence

British Dictionary definitions for dictionary


/ (ˈdɪkʃənərɪ, -ʃənrɪ) /

nounplural -aries
    • 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

    • 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

    • (as modifier): a dictionary definition See also glossary, lexicon, thesaurus

  1. 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

  1. a collection of information or examples with the entries alphabetically arranged: a dictionary of quotations

Origin of 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