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Synonyms

assure

American  
[uh-shoor, uh-shur] / əˈʃʊər, əˈʃɜr /

verb (used with object)

assured, assuring
  1. to declare earnestly to; inform or tell positively; state with confidence to.

    She assured us that everything would turn out all right.

  2. to cause to know surely; reassure.

    He assured himself that no one was left on the bus.

  3. to pledge or promise; give surety of; guarantee.

    He was assured a job in the spring.

  4. to make (a future event) sure; ensure.

    This contract assures the company's profit this month.

  5. to secure or confirm; render safe or stable.

    to assure a person's position.

  6. to give confidence to; encourage.

  7. Chiefly British. to insure, as against loss.


assure British  
/ əˈʃʊə /

verb

  1. to cause to feel sure or certain; convince

    to assure a person of one's love

  2. to promise; guarantee

    he assured us that he would come

  3. to state positively or with assurance

  4. to make (an event) certain; ensure

  5. to insure against loss, esp of life

  6. 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 assureensure, 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

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

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.

The buildings will also have to be signed off by NHS Assure, a national body set up to improve the safety of healthcare facilities, he added.

From BBC • Mar. 19, 2026

Delayed NTCs have opened in Kirkcaldy and Inverness this year but both projects failed to get the support of NHS Assure experts during reviews that took place during the final months of their construction.

From BBC • Jul. 19, 2023

But NHS Assure has found issues with a number of them, including plans for a new modular-built orthopaedics centre at Forth Valley Royal Hospital.

From BBC • Jul. 19, 2023

“Please Keep The Magic Alive!! And always allow the fans of all ages access 2 take pics in front of your home. They will B eternally GR8FUL I Assure U! Good Luck Dude!”

From Los Angeles Times • Jan. 17, 2023

Assure her of my favour, only she must take care of her voice.

From Count Br?hl by Kraszewski, Jo?zef Ignacy