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

re·duce (rĭ-ds, -dys)
Share:
v. re·duced, re·duc·ing, re·duc·es
v.tr.
1. To bring down, as in extent, amount, or degree; diminish. See Synonyms at decrease.
2. To bring to a humbler, weaker, difficult, or forced state or condition; especially:
a. To gain control of; subject or conquer: "a design to reduce them under absolute despotism" (Declaration of Independence).
b. To subject to destruction: Enemy bombers reduced the city to rubble.
c. To bring to a specified undesirable state, as of weakness or helplessness: disease that reduced the patient to emaciation; teasing that reduced the child to tears.
d. To compel to desperate acts: The Depression reduced many to begging on street corners.
e. To lower in rank or grade; demote.
3. To thicken or intensify the flavor of (a sauce, for example) by slow boiling.
4. To lower the price of: The store has drastically reduced winter coats.
5. To decrease the viscosity of (paint, for example), as by adding a solvent.
6. To put in a simpler or more systematic form; simplify or codify: reduced her ideas to a collection of maxims.
7. To turn into powder; pulverize.
8. Chemistry
a. To decrease the valence of (an atom) by adding electrons.
b. To remove oxygen from (a compound).
c. To add hydrogen to (a compound).
d. To change to a metallic state by removing nonmetallic constituents; smelt.
9. Mathematics To simplify the form of (an expression, such as a fraction) without changing the value.
10. Medicine To restore (a fractured or displaced body part) to a normal condition or position.
11. Linguistics To pronounce (a stressed vowel) as the unstressed version of that vowel or as schwa.
v.intr.
1. To become diminished.
2. To lose weight, as by dieting.
3. Biology To undergo meiosis.

[Middle English reducen, to bring back, from Old French reducier, from Latin redūcere : re-, re- + dūcere, to lead; see deuk- in the Appendix of Indo-European roots.]

re·ducer n.
re·duci·bili·ty n.
re·duci·ble adj.
re·duci·bly adv.

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.