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

Definition of assure

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)

Synonyms & Antonyms for assure



Visit the Thesaurus for More 

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 Ukraine won the cheers of the world by agreeing to give them up, in return for promises that the U.S. and Russia would assure its security. Gerald F. Seib, WSJ, 9 May 2022 Doctors overwhelmingly want to assure parents that, while alarming, these cases are rare. Erika Edwards, NBC News, 6 May 2022 By taking steps that assure employees that their needs are being taken care of, managers can boost the performance and productivity of their teams, even in a remote workplace. Anand Inamdar, Forbes, 3 May 2022 Martin said the department, which posted notice of the flyers on its Facebook page, also wanted to assure residents that police are aware of the incident. Jesse Leavenworth, Hartford Courant, 26 Apr. 2022 NFTs are virtual items that use blockchain technology and smart contracts to assure each item is unique and unchangeable. . Khristopher J. Brooks, CBS News, 28 Apr. 2022 And assure them not only that their opinions matter in your decisions, but that onboarding and training will be part of the package. Jim Berryhill, Forbes, 26 Apr. 2022 When your mom is on vacation, assure her that her plants are in great hands with a sleek, self-watering planter. Brittney Morgan And Medgina Saint-elien, House Beautiful, 20 Apr. 2022 This advice has long been standard, though cybersecurity experts have come out in recent years to assure internet users that a password change is likely unnecessary with a strong, unique password. Orlando Mayorquin, USA TODAY, 19 Apr. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'assure.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of assure

14th century, in the meaning defined at sense 4

History and Etymology for assure

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

Learn More About assure

Time Traveler for assure

Time Traveler

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

See more words from the same century

Statistics for assure

Last Updated

15 May 2022

Cite this Entry

“Assure.” Dictionary, Merriam-Webster, Accessed 19 May. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for assure


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

Kids Definition of assure

1 : to give certainty, confidence, or comfort to He assured the children all was well. She assured herself that the doors were locked.
2 : to inform positively I assure you that you won't be disappointed.
3 : to provide a guarantee of assure their safety Hard work assures success.


transitive verb
assured; assuring

Legal Definition of assure

1 chiefly British : insure
2a : to inform positively the seller assured the buyer of his honesty
b : to provide a guarantee of

More from Merriam-Webster on assure

Nglish: Translation of assure for Spanish Speakers

Britannica English: Translation of assure for Arabic Speakers


Test Your Vocabulary

Eponyms: Words Named After People

Spell It

Can you spell these 10 commonly misspelled words?

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!