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

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

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

test 1 (tĕst)
Share:
n.
1. A procedure for critical evaluation; a means of determining the presence, quality, or truth of something; a trial: a test of one's eyesight; subjecting a hypothesis to a test; a test of an athlete's endurance.
2. A series of questions, problems, or physical responses designed to determine knowledge, intelligence, or ability.
3. A basis for evaluation or judgment: "A test of democratic government is how Congress and the president work together" (Haynes Johnson).
4. Chemistry A physical or chemical change by which a substance may be detected or its properties ascertained.
5. A cupel.
v. test·ed, test·ing, tests
v.tr.
1. To subject to a test; try: tested the pen by scribbling on scrap paper; testing job applicants.
2. To reveal the degree of (a given quality) in someone or something by or as if by means of a test: The experiment tested the rats' ability to solve spatial problems. The long war tested the country's resolve.
3.
a. To identify the presence or amount of one or more substances in: tested the water for lead.
b. To identify the amount of (a substance) in something: tested the nitrogen and phosphorus in the soil.
c. To ascertain the properties of: tested the steel for hardness and tensile strength.
d. To assay (metal) in a cupel.
v.intr.
1. To undergo a test.
2. To administer a test: test for acid content; test for the presence of an antibody.
3. To achieve a score or rating on tests: tested high on the entrance exams.
4. To exhibit a given characteristic when subjected to a test: test positive for the tubercle bacillus.

[Middle English, cupel, from Old French, pot, from Latin testū, testum.]

testa·bili·ty n.
testa·ble adj.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
test 2 (tĕst)
Share:
n.
A hard external covering, as that of certain amoebas, dinoflagellates, and sea urchins.

[Latintesta, shell.]
(click for a larger image)
test2
of a sea urchin

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. 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.

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.