ensure

American  

[en-shoor, -shur] / ɛnˈʃʊər, -ˈʃɜr /

verb (used with object)

ensured, ensuring

1. to secure or guarantee.

   This letter will ensure you a hearing.

2. to make sure or certain.

   measures to ensure the success of an undertaking.

3. to make secure or safe, as from harm.

   Synonyms:

   safeguard, guard, protect

4. insure.

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ensure British  

/ -ˈʃɔː, ɛnˈʃʊə /

verb

1. (may take a clause as object) to make certain or sure; guarantee

   this victory will ensure his happiness

2. to make safe or secure; protect

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Usage

What's the difference between ensure, insure, and assure? 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. 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. 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:ensure = make sureinsure = cover with insuranceassure = reassureHere’s an example of ensure, insure, and assure 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 ensure, insure, and assure.

Other Word Forms

• ensurer noun
• unensured adjective

Etymology

Origin of ensure

First recorded in 1350–1400; Middle English ensuren, from Anglo-French enseurer; see en- ¹ ( def. ), sure ( def. )

Explanation

When you ensure that something will happen, you guarantee it. All that homework will ensure that you have no time for fun this afternoon! Ensure comes from the Old French en- "make" plus seur "sure," and that is exactly what it means today - "to make sure or certain, to guarantee." If you ensure success or someone's safety, you are guaranteeing it. Make sure you can really come through with something before you ensure it!

Example Sentences

In a note to clients this week, Morgan Stanley’s Andrew Percoco said the investment is needed to ensure Tesla’s leadership in artificial intelligence and autonomous technologies.

From MarketWatch • Apr. 24, 2026

Lionsgate has done advanced work to ensure that a significant amount of the previously captured footage could be included.

From Los Angeles Times • Apr. 24, 2026

"The booklet has been removed from circulation, and we are reviewing processes to ensure this doesn't happen again."

From BBC • Apr. 24, 2026

Still, Atago, a former BOJ official, said that when economic shocks occur, central banks need to ensure there is enough liquidity for funds to reach those in need instead of raising interest rates.

From The Wall Street Journal • Apr. 24, 2026

“Everything’s perfect. I will watch over you as you sleep and ensure the safety of your legs from mosquitoes.”

From "Healer of the Water Monster" by Brian Young

Related Words

• assure
• establish
• insure
• protect
• provide
• safeguard
• secure