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

“We cannot assure you that we will achieve our Company Purpose or that the expected positive impact...will be realized,” it acknowledges in the prospectus.

From Los Angeles Times ● Oct. 28, 2026

More than once, I found myself studying photographs of grocery shelves, circling the very products I’d requested and sending the images back to my shopper, who would politely assure me that they weren’t available.

From Salon ● Oct. 25, 2026

But concerns are rising that the virus could start spreading further, even as the government has sought to assure citizens.

From BBC ● Oct. 20, 2026

“I cannot assure the committee, or you chair… that that is it,” Duff Gordon says in response to a question from the committee chair on whether further incidents should be expected.

From The Wall Street Journal ● Oct. 14, 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

The move assures that Watt will call his first Super Bowl on Feb. 13, 2028, in Atlanta.

From Los Angeles Times ● Oct. 22, 2026

When it falsely assures that sufficient oversight has been provided, this is worse than no oversight.

From The Wall Street Journal ● Sep. 15, 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

“There is no need to worry,” El Li'der assures them.

From "Dreaming in Cuban" by Cristina García

For closer connections, the same level of accuracy could not always be assured.

From Science Daily ● Oct. 30, 2026

As global budgets have assured Maryland hospitals growing revenue for treating fewer patients, the cost of common inpatient procedures from 2008 to 2022 increased by 7% to 34% more than nationwide.

From The Wall Street Journal ● Oct. 30, 2026

Prime Minister Pedro Sanchez assured the affected families that "all branches of the state are working tirelessly... to try to give and provide the most information possible, as soon as possible, reliably."

From Barron's ● Oct. 30, 2026

Australia - already assured of a semi-final place - have made several changes.

From BBC ● Oct. 27, 2026

Mother assured him that was not going to happen, but still Father kept delaying our departure, until we were among the very last to leave.

From "Across So Many Seas" by Ruth Behar

She has remained a tireless democracy campaigner on social media, where she regularly posts videos assuring Venezuelans that change is near at hand.

From Barron's ● Oct. 25, 2026

When the first case was announced, the authorities urged people not to panic, assuring them of heightened surveillance at airports and border crossings.

From BBC ● Oct. 20, 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

But every time it comes up, tech leaders always seem to be hedging: assuring us that limits are high, adjustable and there’s always a process for increasing them.

From The Wall Street Journal ● Sep. 10, 2026

For months, Johnson had been assuring Americans that he had no intention of expanding the country’s role in Vietnam.

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

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