use-icon

HOW TO USE THE DICTIONARY

Learn what the dictionary tells you about words.

Get Started Now!

Some compound words (like bus rapid transit, dog whistle, or identity theft) don’t appear on the drop-down list when you enter them into the search window. If a compound term doesn’t appear in the drop-down list, try entering the term into the search window and then hit the search button (instead of the “enter” key). Alternatively, begin searches for compound terms with a quotation mark.

use-icon

THE USAGE PANEL

The Usage Panel is a group of nearly 200 prominent scholars, creative writers, journalists, diplomats, and others in occupations requiring mastery of language. The Panelists are surveyed annually to gauge the acceptability of particular usages and grammatical constructions.

The Panelists

puzzle-icon

NEED HELP SOLVING A CROSSWORD PUZZLE?

Go to our Crossword Puzzle Solver and type in the letters that you know, and the Solver will produce a list of possible solutions.

open-icon

INTERESTED IN DICTIONARIES?

Check out the Dictionary Society of North America at http://www.dictionarysociety.com

open-icon

AMERICAN HERITAGE DICTIONARY APP

The new American Heritage Dictionary app is now available for iOS and Android.

scroll-icon

INDO-EUROPEAN & SEMITIC ROOTS APPENDICES

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

open-icon

OPEN DICTIONARY PROJECT

Share your ideas for new words and new meanings of old words!

Start Sharing Now!

100-words-icon

See word lists from the best-selling 100 Words Series!

Find out more!

func·tion (fŭngkshən)
Share:
n.
1. The action or purpose for which a person or thing is suited or employed, especially:
a. A person's role or occupation: in my function as chief editor.
b. Biology The physiological activity of an organ or body part: The heart's function is to pump blood.
c. Computers A procedure within an application.
2. An official ceremony or a formal social occasion: disliked attending receptions and other company functions.
3. Something closely related to another thing and dependent on it for its existence, value, or significance: Growth is a function of nutrition.
4. Abbr. f Mathematics
a. A variable so related to another that for each value assumed by one there is a value determined for the other.
b. A rule of correspondence between two sets such that there is exactly one element in the second set assigned to each element in the first set. Also called mapping.
intr.v. func·tioned, func·tion·ing, func·tions
1. To have or perform a function; serve: functioned as ambassador.
2. To deal with or overcome the challenges of everyday life: For weeks after his friend's funeral he simply could not function.

[Latin fūnctiō, fūnctiōn-, performance, execution, from fūnctus, past participle of fungī, to perform, execute.]

function·less adj.

Synonyms: function, duty, office, role
These nouns denote the actions and activities assigned to, required of, or expected of a person: the function of a teacher; a bank clerk's duty; performed the office of financial adviser; the role of a parent.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 

This website is best viewed in Chrome, Firefox, Microsoft Edge, or Safari. Some characters in pronunciations and etymologies cannot be displayed properly in Internet Explorer.