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



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



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



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


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

Find out more!



Check out the Dictionary Society of North America at

se·vere (sə-vîr)
adj. se·ver·er, se·ver·est
1. Unsparing, harsh, or strict, as in treatment of others: a severe critic.
2. Marked by or requiring strict adherence to rigorous standards or high principles: a severe code of behavior.
3. Stern or forbidding, as in manner or appearance: spoke in a severe voice.
4. Extremely plain in substance or style: a severe black dress.
5. Causing great discomfort, damage, or distress: a severe pain; a severe storm.
6. Very dangerous or harmful; grave or grievous: severe mental illness.
7. Extremely difficult to perform or endure; trying: a severe test of our loyalty.

[Latin sevērus, serious, strict; see segh- in the Appendix of Indo-European roots.]

se·verely adv.
se·vereness n.

Synonyms: severe, stern1, austere, ascetic, strict
These adjectives mean unsparing and exacting with respect to discipline or control. Severe implies adherence to rigorous standards or high principles and often suggests harshness: "Praise or blame has but a momentary effect on the man whose love of beauty in the abstract makes him a severe critic on his own works" (John Keats).
Stern suggests unyielding disposition, uncompromising resolution, or forbidding appearance or nature: "She was a stern woman who ran the household with precision and an iron hand" (Margaret Truman).
Austere connotes aloofness or lack of feeling or sympathy, and often rigid morality: "The captain ... was an austere man that never laughed or smiled that one could see" (Alan Paton).
Ascetic suggests self-discipline and often renunciation of worldly pleasures for spiritual improvement: "Be systematically ascetic ... do ... something for no other reason than that you would rather not do it" (William James).
Strict means requiring or showing stringent observance of obligations, rules, or standards: "She was afraid to wake him up because even in his sleep he seemed to be such a strict man" (Eudora Welty).

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.