beware

American  

[bih-wair] / bɪˈwɛər /

verb (used with object)

1. to be wary, cautious, or careful of (usually used imperatively).

   Beware such inconsistency. Beware his waspish wit.

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verb (used without object)

1. to be cautious or careful.

   Beware of the dog.

beware British  

/ bɪˈwɛə /

verb

1. to be cautious or wary (of); be on one's guard (against)

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Usage

What does beware mean? Beware means be careful or cautious—watch out for danger or other bad stuff. Beware is a command (or at least a suggestion). Sometimes, it’s used by itself, as in Beware! There are dark forces afoot! More commonly, it’s immediately followed by the specific thing you should beware of, as in Beware the words of politicians. Perhaps most commonly, it’s paired with the word of, such as on a sign that says Beware of cat. (You thought we were going to say Beware of dog, didn’t you? Stay alert, folks. Beware a wily dictionary.)Example: Before you enter the internet, there should be a sign that says “Beware of trolls.”

Etymology

Origin of beware

1150–1200; Middle English, from phrase of warning be ware. See be, ware ²

Explanation

To beware is to be cautious and on your guard. The riskier the situation, the more you need to beware. A "Beware of the dog" sign means there's a dog in the house who doesn't care for visitors or new people. When you beware, you become very cautious. You look both ways and use extreme caution. This word can be remembered if you break it into two parts: to beware is the same as "to be wary." When you're wary, you're concerned and careful. People in dangerous jobs like the police and fire department need to beware every day.

Example Sentences

When it comes to choosing a Medicare Advantage plan, now more than ever, buyers must beware.

From MarketWatch • Apr. 24, 2026

But things change, and beware of Matsumoto, the pitcher.

From Los Angeles Times • Apr. 1, 2026

Given wild intraday market gyrations, to catch a market downswing you may have to act quickly—but beware: Hasty moves can lead to costly errors, says Ed Slott, president of Ed Slott & Co.

From Barron's • Mar. 21, 2026

At home, he warned citizens to beware of extreme partisanship.

From BBC • Jan. 8, 2026

‘Did I not say to you: if you pass the doors of Moria, beware? Alas that I spoke true! What hope have we without you?’

From "The Fellowship of the Ring" by J.R.R. Tolkien

Related Words

• heed
• take care