Is there an idiom in English to describe someone who thinks he/she is smarter/wiser than everyone else?

In Polish, we have an idiom, which literally translated, would sound like:

He/she has eaten all minds

  • US=smarty-pants. UK=smart aleck. Jan 11, 2013 at 19:32

6 Answers 6


In English, a common term for such a person is "know-it-all", as in:

Ever since Bob took that first-year philosophy course, he's acting like such a know-it-all.

Usually the phrase has a slightly negative connotation to it, because it implies that the person really doesn't know it all, but they might act arrogant as if they do know it all.

  • With typical Australian economy of language, Bob would be a "know-all". We don't like to waste syllables.
    – Fortiter
    Jan 12, 2013 at 10:06

There are numerous amusing English terms for such a person, including
wiseacre (“One who feigns knowledge or cleverness; an insolent upstart”),
smarty-pants (“A smart aleck or know-it-all”),
clever dick (“(chiefly UK) A person who annoyingly tries too hard to impress with their cleverness”),
smart aleck (“One who is pretentious about their own cleverness or knowledge; a know-it-all”, but also with senses “One who is obnoxiously self-assured; a show off” and “One who is given to obnoxious or insolent humor; a wise guy”).

Some terms related to the above, but with slightly different meanings, include
wiseass (“One who makes wisecracks, particularly in a sassy or cocky fashion”),
smartass (“(slang) One who is particularly insolent, who tends to make snide remarks or jokes”).

  • 1
    I go along with a couple of these but also see them being applied more so to a (how to describe this without using one of your words?) . . . person who always tries to crack a joke or make fun of someone. (I was going to use "wisenheimer" but discovered it actually is a better word for the OP's intent than some others!) :-) Jan 11, 2013 at 19:58
  • 1
    good, but they are not as poetic as 'eating all minds' ;) Jan 11, 2013 at 20:47

Though "know-it-all" is my #1 go-to phrase for that meaning, another expression with a smart-alecky negative connotation would be to refer to someone as "Einstein", as in:

"Einstein, here, has all the answers!"

Of course, the reference would be to Albert Einstein, the theoretical physicist:

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How about: "He[she] is full of himself[herself]"? That's a pretty common English idiom.


Focusing on the wiser aspect:


Characterized by an attitude of moral superiority



Charlatan is the word to describe such person

  • 2
    Welcome to ELU! Can you please include a definition from a dictionary that describes the characteristics of a "Charlatan"? That would be helpful to our users as they are from all over the world and not all words are known internationally. Jan 11, 2013 at 23:37
  • 2
    I wouldn't use the word charlatan in the context the O.P. mentions unless I wanted to also imply a sense of dishonesty or delusion.
    – J.R.
    Jan 12, 2013 at 0:18

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