assure

verb

as·​sure ə-ˈshu̇r How to pronounce assure (audio)
assured; assuring

transitive verb

1
: to make sure or certain : convince
glancing back to assure himself no one was following
2
: to inform positively
I assure you that we can do it.
3
: to make certain the coming or attainment of : guarantee
worked hard to assure accuracy
4
: to make safe (as from risks or against overthrow) : insure
assured the security of the country
5
: to give confidence to
And hereby we know that we are of the truth, and shall assure our hearts …1 John 3:19 (King James Version)
Choose the Right Synonym for assure

ensure, insure, assure, secure mean to make a thing or person sure.

ensure, insure, and assure are interchangeable in many contexts where they indicate the making certain or inevitable of an outcome, but ensure may imply a virtual guarantee

the government has ensured the safety of the refugees

, while insure sometimes stresses the taking of necessary measures beforehand

careful planning should insure the success of the party

, and assure distinctively implies the removal of doubt and suspense from a person's mind.

I assure you that no harm will be done

secure implies action taken to guard against attack or loss.

sent reinforcements to secure their position

Examples of assure in a Sentence

I can assure you that you won't be disappointed. a minister choosing just the right words to assure the grieving parents of the fallen soldier
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Around the same time the Childers concert pictures leaked, a source once again went to People to assure the masses that all is well for NepoLand’s favorite chill couple. Elizabeth Logan, Glamour, 17 June 2025 However, she was assured that everything would be safe. Michael Nied, People.com, 17 June 2025 Invariably, a huge tomato graced the cover, assuring frost-weary householders with the promise of summer. Danny Heitman, Christian Science Monitor, 17 June 2025 Alice's Kids plans to cover the cost of prom for more than 800 students, assuring their chance to attend the annual high school rite of passage. Mekishana Pierre Published, EW.com, 16 June 2025 See All Example Sentences for assure

Word History

Etymology

Middle English, from Anglo-French asseurer, assurer, from Medieval Latin assecurare, from Latin ad- + securus secure

First Known Use

14th century, in the meaning defined at sense 4

Time Traveler
The first known use of assure was in the 14th century

Cite this Entry

“Assure.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/assure. Accessed 26 Jun. 2025.

Kids Definition

assure

verb
as·​sure ə-ˈshu̇(ə)r How to pronounce assure (audio)
assured; assuring
1
: to provide a guarantee of
assure security
2
: to give words of comfort or confidence to : reassure
tried to assure the worried children
3
: to cause to be sure or certain
assure himself that the door was locked
4
: to inform positively
can assure you of her dependability

Legal Definition

assure

transitive verb
as·​sure
assured; assuring
1
chiefly British : insure
2
a
: to inform positively
the seller assured the buyer of his honesty
b
: to provide a guarantee of

More from Merriam-Webster on assure

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