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.”

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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

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

Local officials have tried to assure residents that they are dealing with a major player in AI, not a fly-by-night operator.

From The Wall Street Journal ● Aug. 16, 2026

I can assure you on Sunday we will compete.

From BBC ● Aug. 8, 2026

I assure you this is less about sisterly solidarity or my lingering affection for “Ted Lasso” or even a love of soccer – er, football.

From Salon ● Aug. 7, 2026

Even Miss Kemp does, I think, because she said, “Alice, I can assure you that by the time Howard gets to ‘someday,’ he won’t even remember this blanket.”

From "The Best School Year Ever" by Barbara Robinson

And for 86 minutes, it assures us that some of the greatest cinematic treasures are also blissfully conflict-free.

From Salon ● Jul. 15, 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

Luis Cardona, the Colombian visitor, has no plans to hit the slopes but assures that, virus or no virus, he would "have no problem returning" to Ushuaia.

From Barron's ● May 12, 2026

New leader says company has shortlist of acquisition targets, as its cash pile grows; assures investors that culture isn’t changing.

From The Wall Street Journal ● May 5, 2026

He assures her that Theo will indeed be very happy if all goes well with her and the baby.

From "Vincent and Theo: The Van Gogh Brothers" by Deborah Heiligman

This John Stewart is purposefully calm and assured, even when Kyle Chandler’s Hal Jordan, an entitled jerk clinging to crusted-over glory, provokes him.

From Salon ● Aug. 31, 2026

Interim leader Delcy Rodriguez assured the public Saturday that Venezuela retains control of its oil under a new agreement that allows the United States significant access to it.

From Barron's ● Aug. 30, 2026

The season opener against the San Francisco 49ers in Australia is looming, so McVay will hold out nearly all players assured of a roster spot, other than perhaps kicking-game specialists.

From Los Angeles Times ● Aug. 26, 2026

No, he assured them when he came back.

From The Wall Street Journal ● Aug. 26, 2026

The mere mention of peas caused the children to voice heartfelt objections, but Miss Mortimer smiled and assured them that something much tastier was on its way.

From "The Interrupted Tale" by Maryrose Wood

The messaging platform, with over 90 million active daily users, agreed to suspend livestreaming in Brazil on August 17, assuring it was working "to make Discord safer for teens."

From Barron's ● Aug. 26, 2026

Some in the real-estate industry encouraged aspiring buyers to “date the rate, marry the house,” assuring them that they could refinance when rates dropped.

From MarketWatch ● Jul. 22, 2026

Yet the administration abandoned its review of the shootings before explaining what had gone wrong — or assuring the public that anything would change.

From Salon ● Jul. 21, 2026

Makary encouraged the company to file a formal appeal, assuring Regenxbio that the application would be reviewed with “fresh eyes,” Simpson said.

From The Wall Street Journal ● Jun. 22, 2026

Nelia Zafón knocked on the door and clasped one of my hands between hers, apologizing for taking so long to stop by and assuring me that everyone was happy to have us here.

From "The Book of Unknown Americans" by Cristina Henríquez

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