Synonyms

strengthen

American

[strengk-thuhn, streng-, stren-] / ˈstrɛŋk θən, ˈstrɛŋ-, ˈstrɛn- /

verb (used with object)

to make stronger; give strength to.

Synonyms:

support, fortify, reinforce, buttress
Phonetics. to change (a speech sound) to an articulation requiring more effort, as from fricative to stop or nongeminate to geminate.

verb (used without object)

to gain strength; grow stronger.

strengthen British

/ ˈstrɛŋθən /

verb

to make or become stronger

"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

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future

Etymology

Origin of strengthen

First recorded in 1250–1300, strengthen is from the Middle English word strengthnen. See strength, -en ¹

Explanation

To strengthen is to make something stronger! Rarr. You can strengthen your muscles by working out, or strengthen your brain by learning new words. Anytime you strengthen something, you're making it more resistant, vigorous, or tough. Taking vitamins can strengthen your immune system so you don't get sick. Lifting weights will strengthen your muscles. A powerful lock will strengthen a door. On computers, a reliable firewall will strengthen your virus protection. If something is weak, it needs to be strengthened. Congrats! You just strengthened your vocabulary by checking out this definition!

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Example Sentences

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:

strengthen strengthens strengthened strengthening

“These laws strengthen the tools, resources and accountability needed to protect residents and help communities respond when emergencies happen,” Newsom said.

From Los Angeles Times ● Sep. 27, 2026

In many cases, it may also strengthen the doctor-patient relationship by focusing treatment more closely on what is actually driving the patient's symptoms.

From Science Daily ● Sep. 27, 2026

The CRT works with tenant farmers to restore soil health, improve biodiversity and strengthen the natural ecosystem while producing food.

From BBC ● Sep. 25, 2026

“Ethiopia and Eritrea both pledged to set aside their differences and work together to strengthen regional peace and stability,” U.S.

From The Wall Street Journal ● Sep. 24, 2026

They would strengthen the gatehouse and deploy the main body of defenders in the immediate area.

From "Redwall" by Brian Jacques

"Any initiative that strengthens Ukraine's already highly capable, but heavily burdened, cyber defence efforts is a welcome development and could provide a valuable force multiplier," he said.

From BBC ● Sep. 23, 2026

As bitcoin strengthens, its relationship with the traditional stock market also has been changing.

From MarketWatch ● Sep. 21, 2026

Lithuanian Foreign Minister Kestutis Budrys in a post on X thanked allies "whose presence helps protect our skies and strengthens our security".

From Barron's ● Sep. 15, 2026

In an earlier study, researchers at Leipzig University had already found that activation with AP503 also strengthens skeletal muscle.

From Science Daily ● Sep. 9, 2026

Appealing to authority—whether by quoting a commonplace or the words of a named source— always strengthens an argument.

From "Words Like Loaded Pistols" by Sam Leith

The expanded analysis strengthened the case that the unusual sediment structures were produced by earthquakes on both fault systems occurring close together in time.

From Science Daily ● Sep. 24, 2026

"With that financial sustainability in mind, we have strengthened both our men's and women's teams during the summer window and our men's team has seen the return of Champions League football to Old Trafford."

From BBC ● Sep. 23, 2026

The overall energy of the trip and the relationships strengthened by shared experience are worth much more than the nickels and dimes you won’t miss in the long run.

From The Wall Street Journal ● Sep. 19, 2026

He said the company would instead invest in journalism that “is differentiated, consequential and difficult to replicate; reporting rooted in our communities and strengthened by sources, investigation, verification, context and judgment.”

From Los Angeles Times ● Sep. 19, 2026

This strengthened the metal but turned it an ugly pinkish-copper color.

From "1491" by Charles C. Mann

On Tuesday a strengthening southerly wind will bring a much warmer day.

From BBC ● Sep. 28, 2026

The Fed lifted rates by 25 basis points last week and pointed to at least one further increase this year, strengthening the dollar as market rate-hike expectations continue to rise.

From The Wall Street Journal ● Sep. 23, 2026

After rapidly intensifying, Polo was still strengthening into the afternoon, the center said.

From Los Angeles Times ● Sep. 22, 2026

Sunny skies will gradually temper the chill, and while most of England and Wales will stay sunny and dry on Thursday strengthening winds will bring increasing cloud to north-western parts of the UK.

From BBC ● Sep. 22, 2026

The breeze was strengthening as we pulled away from the pier.

From "Beyond the Bright Sea" by Lauren Wolk

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