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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

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

Which implies that, yes, the age of the print dictionary must be passing. —Literary Hub, 29 Sep. 2025

In the dictionary, his name stands for boldness or determination in facing great danger. —Lucy Notarantonio, MSNBC Newsweek, 28 Sep. 2025

The dictionary is available for preorder now, according to Merriam-Webster. —Natalie Neysa Alund, USA Today, 25 Sep. 2025

Call it the paradox of the modern dictionary. —Stefan Fatsis, The Atlantic, 13 Sep. 2025

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

Rhymes for dictionary

• accessary
• adversary
• ancillary
• arbitrary
• aviary
• axillary
• beriberi
• breviary
• budgetary
• capillary
• catenary
• cautionary

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