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dictionary

noun

dic·​tio·​nary ˈdik-shə-ˌner-ē 

-ˌne-rē

plural dictionaries

1

: a reference source in print or electronic form containing words usually alphabetically arranged along with information about their forms, pronunciations, functions, etymologies, meanings, and syntactic and idiomatic uses

2

: a reference book listing alphabetically terms or names important to a particular subject or activity along with discussion of their meanings and applications

3

: a reference book listing alphabetically the words of one language and showing their meanings or translations in another language

4

: a computerized list (as of items of data or words) used for reference (as for information retrieval or word processing)

Synonyms

• lexicon
• wordbook

Examples of dictionary in a Sentence

Famed for his dictionary, "Rambler" essays and The Lives of the English Poets, Samuel Johnson (1709-1784) remains one of the most-quoted and carefully observed authors who ever lived. —Publishers Weekly, 21 July 2008

I still read relatively slowly in Yiddish, with frequent recourse to a dictionary, and my first year of graduate school found me at my desk till two or three in the morning every night … —Aaron Lansky, Outwitting History, 2004

Look it up in the dictionary.

try to develop the habit of going to the dictionary whenever you encounter an unfamiliar word

Recent Examples on the Web

Plus, snag a best-selling LeapFrog dictionary and a large box of Lego bricks. —Phoebe Sklansky, Parents, 8 July 2024

The ruling penned by Justice Clarence Thomas tortured the dictionary in differentiating shots fired from a single pull of a trigger to those fired as a bump stock keeps a weapon pushing up against a shooter’s trigger pull. —New York Daily News Editorial Board, New York Daily News, 17 June 2024

Merriam-Webster said its embrace of the shorter spelling is in line with the philosophy of Noah Webster, whose early dictionaries set the tone for the brand. —Cybele Mayes-Osterman, USA TODAY, 7 June 2024

Simply using a French-English dictionary to translate word by word doesn’t work, as different languages have different structures, and words have different meanings in different contexts. —Quanta Magazine, 12 June 2024

Word History

Etymology

borrowed from Medieval Latin dictiōnārium, name for an alphabetized guide to the Vulgate, earlier dictiōnārius, name for a Latin textbook in which words are grouped by topic (apparently coined by its author, the 13th-century English-born university teacher John of Garland), from Latin dictiōn-, dictiō "speech, (in grammar) word, expression" + -ārius, -ārium -ary entry 1 — more at diction

First Known Use

1526, in the meaning defined at sense 1

Kids Definition

dictionary

noun

dic·​tio·​nary ˈdik-shə-ˌner-ē 

plural dictionaries

1

: a reference source in print or electronic form giving information about the meanings, forms, pronunciations, uses, and origins of words listed in alphabetical order

2

: a reference book that lists in alphabetical order terms or names important to a particular subject along with explanations of their meanings and uses

a law dictionary

3

: a reference book giving words of one language and their meanings in another

an English-French dictionary

Etymology

from Latin dictionarium "dictionary," from earlier diction-, dictio- "words, speaking," from dicere "to say" — related to dictate