ensure

[ en-shoor, -shur ]

verb (used with object)

, en·sured, en·sur·ing.

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 ( defs 1, 2, 3 ).

ensure

/ -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

Derived Forms

• enˈsurer, noun

Other Words From

• en·surer noun
• unen·sured adjective

Word History and Origins

Origin of ensure¹

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

Example Sentences

Passengers should arrive two hours before their departure time, or three hours if traveling internationally, and book parking ahead of time to ensure a spot on days where parking structures are expected to reach capacity.

From Los Angeles Times

“It was my responsibility to ensure the soldiers under me didn’t take any phones on to the nuclear base,” he explains.

From BBC

Blockchain, a decentralised digital ledger technology that ensures transparency and data integrity, is the foundation of this functionality.

From Science Daily

Ms Plunkett is comfortable with digital tools - her business advises companies on how to ensure their online content is suitable for the visually impaired community.

From BBC

They argue that sex is a “matter of biological fact”, and that “the ordinary, biological meaning of sex is necessary to ensure the rights and protections provided to women”.

From BBC

Related Words

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

Ensure Vs. Insure Vs. Assure

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 sure
insure = cover with insurance
assure = reassure

Here’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.

Quiz yourself on ensure vs. insure vs. assure!

Should ensure, insure, or assure be used in the following sentence?

We need to take action to _____ that this never happens again.