American

[dih-krees, dee-krees, dih-krees] / dɪˈkris, ˈdi kris, dɪˈkris /

verb (used without object)

decreases,
present (3rd person singular)
decreased,
past participle, past
decreasing
present participle

to diminish or lessen in extent, quantity, strength, power, etc..

During the ten-day march across the desert their supply of water decreased rapidly.

Synonyms:

abate, contract, decline, lessen, wane

Antonyms:

expand, increase

verb (used with object)

decreases,
present (3rd person singular)
decreased,
past participle, past
decreasing
present participle

to make less; cause to diminish.

to decrease one's work load.

noun

decreases
plural

the act or process of decreasing; condition of being decreased; gradual reduction.

a decrease in sales;
a decrease in intensity.

Synonyms:

subsidence, decline, abatement
the amount by which a thing is lessened.

The decrease in sales was almost 20 percent.

decrease British

verb

to diminish or cause to diminish in size, number, strength, etc

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

the act or process of diminishing; reduction
the amount by which something has been diminished

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Usage

What does decrease mean? To decrease is to lessen or become reduced in number, amount, size, or in some other way, as in Our profits will continue to decrease unless we cut costs. As a verb, decrease is also used in an active way in which someone or something is doing the decreasing, as in I’m going to decrease my hours at work or These sunglasses decrease glare. The word reduce is perhaps even more commonly used to mean the same thing. Decrease can also be used as a noun referring to a reduction, as in We are experiencing a decrease in applicants. It can also refer to the amount by which something has decreased, as in The decrease was $5,000 per year. The words decreased and decreasing can both be used as adjectives, as in a decreased appetite or decreasing sales. The opposite of decrease as both a verb and a noun is increase. Example: Sally decided to decrease her workload, which led to a decrease in stress.

Synonym Usage

Decrease, diminish, dwindle, shrink imply becoming smaller or less in amount. Decrease commonly implies a sustained reduction in stages, especially of bulk, size, volume, or quantity, often from some imperceptible cause or inherent process: The swelling decreased daily. Diminish usually implies the action of some external cause that keeps taking away: Disease caused the number of troops to diminish steadily. Dwindle implies an undesirable reduction by degrees, resulting in attenuation: His followers dwindled to a mere handful. Shrink especially implies contraction through an inherent property under specific conditions: Many fabrics shrink in hot water.

Other Word Forms

Derived Forms

Inflected Forms

decreases

plural

Conjugated Forms

Etymology

Origin of decrease

First recorded in 1350–1400; Middle English verb decresen, from Old French decreiss-, long stem of decreistre, from Latin dēcrēscere “to diminish,” literally “to grow down,” equivalent to dē- de- + crēscere “to grow”); noun derivative of the verb; see crescent

Explanation

Decrease means to lower or go down. If you are driving above the speed limit, you should decrease your speed or risk getting a ticket. Students always want teachers to decrease the amount of homework. The opposite of decrease is increase, which means to raise. In science, you often are measuring increases and decreases. Is there a decrease in the time it takes water to boil when you begin with water as a liquid rather than water in its ice-cube form?

Keep Reading on Vocabulary.com

Vocabulary lists containing decrease

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

decrease decreases decreased decreasing

Research has shown that roughly half the decline in the river’s flow is because of higher temperatures, and for each 1.8 degrees Fahrenheit the region warms, the flow is likely to decrease about 9%.

From Los Angeles Times ● Aug. 18, 2026

“The latest decrease was driven mainly by smaller businesses, which cite labor and operating costs as reasons for not hiring new staff or replacing leavers,” McKeown added.

From The Wall Street Journal ● Aug. 18, 2026

He told BBC Radio 4's Today programme his organisation had seen a decrease in the number of wildfires emergency services have responded to in the last 72 hours.

From BBC ● Aug. 17, 2026

Every factor of 10 decrease in loss produces a factor of 100 improvement in coherence.

From Science Daily ● Aug. 17, 2026

As they expanded, the energy of the field in them would slowly decrease until the inflationary expansion changed to an expansion like that in the hot big bang model.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

The effect would have been the opposite in prior years, rendering two successive decreases in citywide homelessness marginally less impressive.

From Los Angeles Times ● Aug. 11, 2026

Public health experts have long advised that the combined shot offers children more protection faster, and also decreases the logistical hurdles for parents who may struggle to make multiple appointments.

From Barron's ● Aug. 10, 2026

Others have said that while small price decreases are welcome, they appreciate the messaging it sends more.

From BBC ● Jul. 27, 2026

"Our findings show that, across different organism groups, extinctions happened at much higher rates for those more vulnerable to increases in water temperature and decreases in oxygen availability."

From Science Daily ● Jul. 12, 2026

These areas would show changes— like increases and decreases in blood flow—when study subjects were trying to focus on something, or when they were overwhelmed with information, putting intensified pressure on the attention networks.

From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel

Physiological reactions to memories of criticism decreased, indicating that recalling distressing experiences no longer triggered the same level of intense stress.

From Science Daily ● Aug. 18, 2026

This includes increased maintenance costs and decreased readiness windows while ships are prepared to deploy again, he said.

From Barron's ● Aug. 13, 2026

While the citywide number has increased, the number of homeless people living on the street in Raman’s district decreased by 49%, a fact she has touted as she challenges Bass.

From Los Angeles Times ● Aug. 10, 2026

While antisemitic incidents decreased in the U.S. overall in 2025 after reaching a record high in 2024, they have remained at elevated levels since 2021, according to a recent report by advocacy group Anti-Defamation League.

From The Wall Street Journal ● Aug. 3, 2026

Experiments show that the motility of bull sperm is decreased by dinitrophenol, which interferes with the energy- coupling mechanism with inevitable loss of energy.

From "Silent Spring" by Rachel Carson

They’ve read the research documenting how the outdoors, including urban green spaces, improves cognition, social connection and physical strength, while decreasing depression and anxiety in all ages, but especially seniors.

From Los Angeles Times ● Aug. 15, 2026

Fossil-fuel power plants have deteriorated over the past few decades, decreasing output.

From The Wall Street Journal ● Aug. 9, 2026

This result suggests that the approach restores the way proteins function rather than simply increasing or decreasing how much of each protein is present.

From Science Daily ● Aug. 7, 2026

There have been concerns that while decreasing temperatures indoors, air conditioning units can increase outdoor temperatures.

From BBC ● Jul. 27, 2026

This expansion is said to be “inflationary,” meaning that the universe at one time expanded at an increasing rate rather than the decreasing rate that it does today.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023