use-icon

HOW TO USE THE DICTIONARY

To look up an entry in The American Heritage Dictionary of the English Language, use the search window above. For best results, after typing in the word, click on the “Search” button instead of using the “enter” key.

Some compound words (like bus rapid transit, dog whistle, or identity theft) don’t appear on the drop-down list when you type them in the search bar. For best results with compound words, place a quotation mark before the compound word in the search window.

guide to the dictionary

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. Annual surveys have gauged the acceptability of particular usages and grammatical constructions.

The Panelists

open-icon

AMERICAN HERITAGE DICTIONARY APP

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

scroll-icon

THE AMERICAN HERITAGE DICTIONARY BLOG

The articles in our blog examine new words, revised definitions, interesting images from the fifth edition, discussions of usage, and more.

100-words-icon

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

Find out more!

open-icon

INTERESTED IN DICTIONARIES?

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

be·hav·ior (bĭ-hāvyər)
Share:
n.
1. The manner in which one acts or behaves.
2.
a. The actions or reactions of a person or animal in response to external or internal stimuli.
b. One of these actions or reactions: "a hormone ... known to directly control sex-specific reproductive and parenting behaviors in a wide variety of vertebrates" (Thomas Maugh II).
3. The manner in which something functions or operates: the faulty behavior of a computer program; the behavior of dying stars.

[Middle English behavour, from behaven, to behave (on the model of havour, behavior, from Old French avoir, from avoir, to have); see BEHAVE.]

be·havior·al adj.
be·havior·al·ly adv.

Synonyms: behavior, conduct, bearing, deportment, comportment, demeanor
These nouns all pertain to a person's actions as they constitute a means of evaluation by others. Behavior is the most general: The children were on their best behavior.
Conduct applies to actions considered from the standpoint of morality and ethics: "Life, not the parson, teaches conduct" (Oliver Wendell Holmes, Jr.)
Bearing often carries with it the implication of social standing or position: "It was evident from his bearing that he belonged to the country's ruling élite" (Amitav Ghosh).
Deportment and comportment pertain more narrowly to actions measured by a prevailing code of social behavior: "the alleged decline in standards of deportmenta significant issue for an institution that prided itself on turning out 'gentlemen'" (Jerome Karabel). "Would I see a different person, or merely the same one governed by different conventions of comportment ... accoutrement, and dress?" (Witold Rybczynski).
Demeanor suggests outward appearance that manifests inward emotion or character: "The Beth I saw now was not only nimble-footed, but her demeanor was exuberant and self-assured" (Rachel Simon).

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
 

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.