Whats a good word to describe someone who isn't easily fooled or isn't gullible?

  • I think the proper word is going to be based on the threshold of "easiness" to fool. For example "astute" would be a good fit for describing someone who doesn't go along with the idea that ostriches hide their head underground. While, skeptical, is based more in doubting as a default position on a topic. Skeptical about our effect on global warming for example. There are other examples of "common sense" or awareness, but they all seem be based on situations and circumstances.
    – coteyr
    Aug 28, 2015 at 23:39
  • I tried to look up antonyms of "gullible" but found that word isn't in the dictionary. Aug 29, 2015 at 10:45

9 Answers 9


Perhaps you can use shrewd or astute. Wary may be also a good fit.

  • 1
    also "distrustful" or "cautious"
    – Graffito
    Aug 28, 2015 at 15:11
  • 1
    also also "discerning" Aug 28, 2015 at 18:31

In the US, we call a person who is quick to "see through" others, "street-smart". While the expression can be used in other ways, it is often a way to describe someone who is not easily deceived.



1. having or showing shrewdness and good judgment, especially in money or business matters "canny shoppers came early for a bargain" synonyms: shrewd, astute, smart, sharp, sharp-witted, ... more


I would expect that a savvy person would not be gullible and would be difficult to fool.


In common use, one might call someone who's very on-guard against being tricked suspicious. This sense of the word is defined by Merriam-Webster as "having or showing a feeling that something is wrong or that someone is behaving wrongly : feeling or showing suspicion". Note that this word can be applied both to the person who suspects something and to the person or thing that they suspect.

Another, perhaps less confrontational, way to describe this person skeptical, which is defined by Merriam-Webster "as having or expressing doubt about something (such as a claim or statement)".


What about a skeptic?

noun skep·tic \ˈskep-tik\ : a person who questions or doubts something (such as a claim or statement) : a person who often questions or doubts things

Skeptics are usually hard to fool or deceive, as they tend to be doubtful until evidence or something shows otherwise.


wise - the definition given by Collins includes shrewd, suggested above.


Along with the other suggestions, keen and perceptive also fit.


Although not specific to being difficult to fool, the word sharp comes to mind.

You won’t fool Charlie, he's a sharp one.

From the Oxford dictionaries online definition of sharp -

Having or showing speed of perception, comprehension, or response:

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