Synonyms

assure

American

[uh-shoor, uh-shur] / əˈʃʊər, əˈʃɜr /

verb (used with object)

to declare earnestly to; inform or tell positively; state with confidence to.

She assured us that everything would turn out all right.
to cause to know surely; reassure.

He assured himself that no one was left on the bus.
to pledge or promise; give surety of; guarantee.

He was assured a job in the spring.
to make (a future event) sure; ensure.

This contract assures the company's profit this month.
to secure or confirm; render safe or stable.

to assure a person's position.
to give confidence to; encourage.
Chiefly British. to insure, as against loss.

assure British

/ əˈʃʊə /

verb

to cause to feel sure or certain; convince

to assure a person of one's love
to promise; guarantee

he assured us that he would come
to state positively or with assurance
to make (an event) certain; ensure
to insure against loss, esp of life
property law another word for convey

"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's the difference between assure, ensure, and insure? Assure usually means to tell someone something with confidence or to cause someone to know something with certainty—it often means the same thing as reassure. Ensure most commonly means to guarantee or make certain, as in Working hard ensures success. Insure typically means to guarantee against loss or harm or, more specifically, to cover with insurance. It’s no wonder there’s confusion between the three words—all three are verbs that are based on the Latin root sēcūrus, meaning safe. Making things even more confusing is the fact that ensure and insure can be used interchangeably in most senses. Still, insure is much more commonly used in the context of insurance, like car insurance, health insurance, and homeowner’s insurance. These kinds of insurance insure you—they give you coverage that provides you with compensation in certain cases and situations. Ensure is typically used in a more general way in the context of actions that are done to make sure that something happens or is the case, as in We need to ensure that the meeting starts on time. Assure is always used in the context of communication, especially in situations in which someone is trying to make someone else feel better about something. It’s used in the phrase rest assured. Here’s a quick cheat sheet to remember the most common uses of each word:assure = reassureensure = make sureinsure = cover with insuranceHere’s an example of assure, ensure, and insure used correctly in a sentence. Example: She assured me that the company has ensured that every employee has the opportunity to be insured. Want to learn more? Read the full breakdown of the difference between assure, ensure, and insure.

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future

Etymology

Origin of assure

First recorded in 1325–75; Middle English as(e)uren, assuren, from Old French aseurer, from Late Latin assēcūrāre, from Latin as- as- + sēcūr(us) ( see secure) + -āre, infinitive suffix

Explanation

If you assure your boss that you’ll finish your project by Tuesday, you are making a promise or commitment to have it done by Tuesday. The verbs insure and ensure look and sound like assure but they aren't synonyms. There is some overlap in meaning — all of them can mean “to make secure or certain” — but assure is generally used in situations when you are referring to a person: “I assure you that I haven’t forgotten about driving you to the airport,” or “He called his mother to assure her that everything will be fine.”

Keep Reading on Vocabulary.com

Vocabulary lists containing assure

"To Kill a Mockingbird" by Harper Lee, Chapters 7–11

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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:

assure assures assured assuring

"And India, I can assure you, is preparing itself for this."

From Barron's ● Sep. 17, 2026

“I regularly interact with international and national leaders, and I want to assure you, we have an international, a national reputation for our work on environmental concerns,” Bass said at the L.A.

From Los Angeles Times ● Sep. 4, 2026

Now that I’ve seen the show – me, and the few thousand other unfortunates rubbernecking at this terrible accident – I’m here to assure you that this was never about us.

From Salon ● Aug. 23, 2026

I appreciate that your goal is to help others, and assure parents who are going through something similar that it does, indeed, get better.

From MarketWatch ● Aug. 21, 2026

“I assure you, madam,” he replied, “that she does not need such advice. She practises very constantly.”

From "Pride and Prejudice" by Jane Austen

“I’m hopeful for a settlement that assures that Paramount and Warner Bros. will maintain their operations and remain a significant economic and employment force in Los Angeles.”

From Los Angeles Times ● Sep. 14, 2026

It assures him of direct entry into the sport's biggest tournaments for the foreseeable future.

From BBC ● Jul. 8, 2026

Galindo assures potential clients, “I’m supportive of all identities and relationship styles so long as they honor the safety of the self & others, physically, emotionally, and otherwise <3.”

From Slate ● May 22, 2026

Though she assures readers that students do suffer consequences, including suspension, for infractions, the goal at HVA is for students to understand what they have done wrong and to make amends.

From The Wall Street Journal ● May 12, 2026

It’s very simple, Todd assures us, just a “matter of taking people who have a very serious problem, though probably not anywhere near as serious as they think it is, and leaving them happy.”

From "Nickel and Dimed: On (Not) Getting By in America" by Barbara Ehrenreich

Others argue that a 4% rate is anything but safe or assured.

From MarketWatch ● Oct. 8, 2026

He then assured the crowd: “We are not going to let that happen. We protect our cities. We protect our country.”

From Los Angeles Times ● Oct. 8, 2026

We know that nuclear war was avoided between the U.S. and Russia because of the bigger picture—both sides eager to avoid mutual assured destruction.

From The Wall Street Journal ● Oct. 5, 2026

Blyth assured multiple information points would be set up in the area over the coming days to offer ongoing reassurance and address concerns.

From BBC ● Sep. 30, 2026

“Oh, Humphrey, I won’t let Clem hurt you. Honest,” Miranda assured me as she gently helped me back in my cage.

From "The World According to Humphrey" by Betty G. Birney

Kenyan authorities have urged people not to panic, with the health ministry assuring of heightened surveillance at airports and border crossings.

From BBC ● Oct. 7, 2026

Gundlach said those private-equity and private-credit firms keep assuring investors there are no problems, and their quarterly figures often won’t reveal any issues.

From MarketWatch ● Oct. 1, 2026

Campbell’s acquired Rao’s, and there are armies of people online who remain convinced that something must have changed, despite Rao’s FAQ explicitly assuring worried customers that the company won’t “touch the sauce.”

From Salon ● Sep. 20, 2026

That support would likely entail Nvidia’s assuring that the value of assets backing loans won’t fall below a predetermined level.

From The Wall Street Journal ● Aug. 25, 2026

The prosecutor rejected this argument, assuring the court no tainted evidence was needed to prove the defendants’ guilt.

From "Most Dangerous: Daniel Ellsberg and the Secret History of the Vietnam War" by Steve Sheinkin

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