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dictionary Syllabification: dic·tion·ar·y
Pronunciation: /ˈdikSHəˌnerē/

Definition of dictionary in English:

noun (plural dictionaries)

1A book or electronic resource that lists the words of a language (typically in alphabetical order) and gives their meaning, or gives the equivalent words in a different language, often also providing information about pronunciation, origin, and usage: I’ll look up ‘love’ in the dictionary the website gives access to an online dictionary [as modifier]: the dictionary definition of ‘smile
More example sentences
  • Apart from in books and dictionaries it was a word that was hardly heard.
  • Mark Twain claimed never to have coined a word as far as he knew, though historical dictionaries list him as the first user of many.
  • The latest dictionary contains new words and phrases that sum up life in the UK today.
lexicon, wordbook, word list, glossary;
1.1A reference work on a particular subject, the items of which are typically arranged in alphabetical order: a dictionary of quotations
More example sentences
  • Instead I had to settle for a couple of old-fashioned dictionaries of quotations.
  • The standard dictionaries of English quotations don't have a single Indian entry.
  • Save for a brief quotation from a dictionary of folklore, I have so far neglected Anglo-Saxon attitudes.
1.2 Computing A set of words or other text strings made for use in applications such as spelling checkers: the worm attempts to crack account passwords using a built-in dictionary
More example sentences
  • It uses a myriad of hacking tools as well as a 340-million-word dictionary to unlock passwords.
  • The first attack is to test a dictionary of about 1,000 common passwords, things like ‘letmein’, ‘password’, ‘123456’ and so on.
  • I wanted to remove the misspelled word from the dictionary, but couldn't figure out how to do it.


Early 16th century: from medieval Latin dictionarium (manuale) or dictionarius (liber) 'manual or book of words', from Latin dictio (see diction).

  • lexicon from early 17th century:

    While a dictionary (early 16th century) goes back to the Latin dicere ‘to speak’, lexicon comes from Greek lexikon (biblion) ‘(book) of words’, from lexis ‘word’, from legein ‘speak’.


have swallowed a dictionary

informal Use long and obscure words when speaking.
Example sentences
  • The reception was held in the Armagh City Hotel and by all accounts everybody swore that Noel had swallowed a dictionary because of all the big words he used during the speech.
  • Hulme seems to have swallowed a dictionary and the results are arch and self-congratulatory.
  • It sounds like someone has swallowed a dictionary and is trying to justify a wishy wash outlook.

Words that rhyme with dictionary

contradictionary • cautionary

Definition of dictionary in:

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