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

stiff (stĭf)
adj. stiff·er, stiff·est
1. Difficult to bend or fold: stiff new shoes; a stiff collar.
a. Not moving or operating easily or freely; resistant: a stiff hinge.
b. Lacking ease or comfort of movement; not limber: a stiff neck.
3. Not liquid, loose, or fluid; thick: stiff dough.
a. Reserved in manner or strict in observing decorum: a stiff commanding officer.
b. Lacking grace or easy charm; very formal: a stiff writing style.
5. Firm, as in purpose; resolute: stiff in their opposition.
6. Having a strong, swift, steady force or movement: a stiff current; a stiff breeze.
7. Potent or strong: a stiff drink.
a. Difficult to deal with, do, or meet: stiff requirements for admission; a stiff examination.
b. Harsh or severe: a stiff penalty.
c. Excessively high or onerous: a stiff price.
9. Nautical Not heeling over much in spite of great wind or the press of the sail.
1. In a stiff manner: frozen stiff.
2. To a complete extent; totally: bored stiff.
1. A corpse.
2. A person regarded as constrained, priggish, or overly formal.
3. A drunk.
4. A person: a lucky stiff; just an ordinary working stiff.
5. A hobo; a tramp.
6. A person who tips poorly.
tr.v. stiffed, stiff·ing, stiffs
1. To tip (someone) inadequately or not at all, as for a service rendered: paid the dinner check but stiffed the waiter.
a. To cheat (someone) of something owed: My roommate stiffed me out of last month's rent.
b. To fail to give or supply (something expected or promised).

[Middle English, from Old English stīf.]

stiffish adj.
stiffly adv.
stiffness n.

Synonyms: stiff, rigid, inflexible, inelastic, tense1
These adjectives describe what is very firm and does not easily bend or give way. Stiff, the least specific, refers to what can be flexed only with difficulty (a brush with stiff bristles); with reference to persons it often suggests a lack of ease, cold formality, or fixity, as of purpose: "stiff in opinions" (John Dryden).
Rigid and inflexible apply to what cannot be bent without damage or deformation (a table of rigid plastic; an inflexible knife blade); figuratively they describe what does not relent or yield: "under the dictates of a rigid disciplinarian" (Thomas B. Aldrich). "In religion the law is written, and inflexible, never to do evil" (Oliver Goldsmith).
Inelastic refers largely to what will not stretch and spring back without marked physical change: inelastic construction materials. By extension it implies an absence of change in the face of changing circumstances: "My little pension is woefully inelastic" (Flann O'Brien).
Tense means stretched tight and figuratively applies to what is marked by tautness or strain: "that tense moment of expectation" (Arnold Bennett).

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.