suspicious

American  

[suh-spish-uhs] / səˈspɪʃ əs /

adjective

1. tending to cause or excite suspicion; questionable.

   suspicious behavior.

   Synonyms:

   doubtful, dubious, suspect

2. inclined to suspect, especially inclined to suspect evil; distrustful.

   a suspicious tyrant.

   Synonyms:

   wary, mistrustful

3. full of or feeling suspicion.

4. expressing or indicating suspicion.

   a suspicious glance.

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suspicious British  

/ səˈspɪʃəs /

adjective

1. exciting or liable to excite suspicion; questionable

2. disposed to suspect something wrong

3. indicative or expressive of suspicion

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Usage

What does suspicious mean? To be suspicious is to have a suspicion about someone or something, especially to have a feeling of distrust about the person or thing. To be suspicious of someone most often involves suspecting that they are engaged in some wrongdoing, as in My parents became suspicious of me when I kept asking whether they’d be home tomorrow. The word is commonly used to describe a person who is suspicious of someone or something in a specific situation. Sometimes, though, it’s used to describe a person who’s suspicious in general—meaning that they’re generally skeptical or distrustful. It can also be used to describe something, such as an action, that indicates that a person is suspicious, as in She gave me a suspicious look that meant she knew I was up to something. Suspicious can also be used to describe someone or something that causes suspicion, as in The guards are trained to identify suspicious people, suspicious behavior, and suspicious packages. Being suspicious is usually based on something, such as a hunch or some kind of evidence, but the word is typically used in situations in which there is some doubt—when someone suspects something, but isn’t sure. The same thing is implied by the verb suspect and the noun suspicion. Suspicious is most commonly used in negative contexts, but this isn’t always the case. For example, you might be suspicious that someone is planning a surprise party for you. Example: Police are encouraging citizens to alert the authorities if they see any suspicious activity on the subway.

Other Word Forms

• hypersuspicious adjective
• hypersuspiciously adverb
• hypersuspiciousness noun
• oversuspicious adjective
• oversuspiciously adverb
• oversuspiciousness noun
• presuspicious adjective
• presuspiciously adverb
• presuspiciousness noun
• self-suspicious adjective
• supersuspicious adjective
• supersuspiciously adverb
• supersuspiciousness noun
• suspiciously adverb
• suspiciousness noun
• unsuspicious adjective
• unsuspiciously adverb
• unsuspiciousness noun

Etymology

Origin of suspicious

First recorded in 1300–50; Middle English, from Latin suspīciōsus, from suspīci(ō) “mistrust” ( suspicion ) + -ōsus -ous

Explanation

Suspicious behavior inspires distrust. Prancing around your backyard in a trench coat and fake mustache during daylight might elicit weird looks from your neighbors; do it at night, though, so that your silhouette glides past their windows, and what appeared innocent enough hours before will quickly transition to suspicious. Use this adjective to describe a behavior or event that arouses doubt or mistrust. How to avoid appearing suspicious? Well, for one, stop pausing mid-conversation to take covert notes in that little journal of yours. And two, don’t wear sunglasses indoors, and don’t try to walk without making a sound. That will make people cagey, which is a synonym for suspicious. Other synonyms include apprehensive, doubtful, wary, and watchful.

Example Sentences

"Legitimate businesses play a critical role in preventing money laundering. Supervised businesses need to stay alert to suspicious activity and put systems in place to protect themselves from exploitation," a spokesperson said.

From BBC • Apr. 10, 2026

The White House asked staff not to use such information after a number of suspicious prediction markets bets.

From The Wall Street Journal • Apr. 10, 2026

I think there is reason to be deeply suspicious of what the OLC is doing here.

From Slate • Apr. 9, 2026

They’re initially suspicious and distrusting of each other.

From Los Angeles Times • Apr. 8, 2026

We greeted her with exclamations of surprise at the happy coincidence, and she did not appear suspicious to find us there.

From "The Detective's Assistant" by Kate Hannigan

Related Words

• apprehensive
• careful
• cautious
• doubtful
• incredulous
• jealous
• leery
• mistrustful
• skeptical
• wary
• watchful