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

overstrengthen verb
prestrengthen verb (used with object)
restrengthen verb
strengthener noun
strengtheningly adverb
unstrengthened adjective
unstrengthening adjective

Etymology

Origin of strengthen

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

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.

“At a time of rampant threats to our democratic system, we must strengthen and defend the integrity of our elections to reaffirm that our government is of, by, and for the people,” she said.

From Los Angeles Times • Apr. 4, 2026

The U.S. company said it would strengthen a tie-up with the country’s cybersecurity office and help the government and businesses detect cyberattacks early or preempt them.

From The Wall Street Journal • Apr. 3, 2026

He argued that closer ties with Europe would strengthen the UK's relationship with the US as well, since successive US presidents had been pushing for Europe to do more on defence and security.

From BBC • Apr. 1, 2026

This deal would strengthen McCormick’s condiments and flavorings portfolio while expanding its North American retail and distribution footprint, said Alex Torgerson, M&A partner at consulting firm West Monroe.

From Barron's • Mar. 31, 2026

The act of eating was a comfort to his shrunken belly, although a false one—the clover wouldn’t strengthen him.

From "Pax" by Sara Pennypacker

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