Is there a word or phrase that describes when a person professes to know about a certain subject, but in fact knows nothing about it?

  • 3
    It depends. Is he lying about knowing it or is he mistaken? Nov 18, 2015 at 22:01
  • Related.
    – tchrist
    Dec 9, 2019 at 5:39

14 Answers 14


A dilettante is a person who's interested in a subject, but doesn't have any real in-depth knowledge about it.

  • 4
    Do you have any research/reference to support your answer? Please include them in your answer. Your interpretation of "dilettante" might be different from others.
    – user140086
    Nov 18, 2015 at 18:04
  • 1
    Thank you LexieLou....this is what I was meaning to find out. Not a synonym, but rather a label. - You've been very helpful!
    – Malia
    Nov 18, 2015 at 18:12
  • 2
    this would seem to have nothing to do with the SWR in question
    – Fattie
    Nov 19, 2015 at 1:29
  • 3
    This refers more to an interest in something rather than professing knowledge in it.
    – 123
    Nov 19, 2015 at 8:30
  • 5
    This answer is actually wrong. A dilettante is someone who dabbles in a lot of subjects, but it's not necessarily someone who professes knowledge but is ignorant. One does not imply the other.
    – Andrew Leach
    Nov 19, 2015 at 16:37

The word quack often applies to those claiming medical knowledge, but it is not limited to that subject:

an unqualified person who claims medical knowledge or other skills (Collins English Dictionary)

a person who pretends, professionally or publicly, to skill, knowledge, or qualifications he or she does not possess; a charlatan. (Random House)

A charlatan meets this description as well:

A person who makes elaborate, fraudulent, and often voluble claims to skill or knowledge; a quack or fraud. (American Heritage Dictionary)

someone who professes knowledge or expertise, esp in medicine, that he or she does not have (Collins English Dictionary)


You could call the person a "poseur" which Merriam-Webster defines as:

: a person who pretends to be what he or she is not : an affected or insincere person

It's pejorative without being profane.


self proclaimed expert
so-called expert

Not exactly what you are looking for but similar flavor.


Sciolist is the most precise.

Oxford dictionary: A person who pretends to be knowledgeable and well informed.

  • 5
    This post would be improved by explaining why you suggest this term, for example, by providing a dictionary definition or examples in the wild. I encourage you take the site tour and review the help center for additional guidance. Nov 19, 2015 at 1:01
  • 4
    A wonderful find. The OED defines the word as "a conceited smatterer." Its origin is the Latin word scire, to know. Scius in Latin means knowing, and sciolus is the diminutive, which is itself an obsolete synonym in English. Go to books.google.com/ngrams and type in "sciolist" in the search box. You will find many happy examples to illustrate the word's use. Please feel free to use the OED information I've given in an answer and add what you find in the ngram viewer. If you do, I'll be happy to upvote.
    – deadrat
    Nov 19, 2015 at 9:32
  • A mnemonic to remember this could be "he's not a sci-entist, he's a sci-olist".
    – ErikE
    Nov 19, 2015 at 19:10
  • @vickyvace, you should also include deadrat's comment: The OED defines the word as "a conceited smatterer." Its origin is the Latin word scire, to know. Scius in Latin means knowing, and sciolus is the diminutive, which is itself an obsolete synonym in English.
    – Mari-Lou A
    Apr 8, 2017 at 11:25

You might be looking for the word claim:

claim, verb. state or assert that something is the case, typically without providing evidence or proof. (Google)

Also related is the word purport:

purport, verb. to claim to be or do a particular thing when this claim may not be true. (M-W)

You might also consider assert, contend, or maintain, although none of these necessarily implies that the speaker "in fact knows nothing about" the topic.


The most obvious option to me is "liar".


How about know-it-all? It is a negative term for someone who behaves as if they know everything.


If the person knows he is misleading others and there are no consequences of the act other than feeding his vanity or social status, then he is a "poseur". If the consequences are a transfer of something of value (money, opportunity, affection) then he is a "fraud". This can even reach the level of illegality if his identity, abilities or services are misrepresented in a contract.

If he does not realize he is "out of his depth", he is merely a fool to be pitied and, if there is a way to do so tactfully, gently informed on the point in question.


Many of those posting answers have assumed that the person knows he is unqualified to speak on the subject and is trying to tease or deceive. This is quite often not the case. Every one of us at times has a plausible but mistaken belief that he is well informed on a topic.

To take striking example, when the Internet first became widely known in 1993, many people with experience in computing and business felt qualified to assess its potential. At dinner parties they offered detailed and highly persuasive arguments backed by specific facts to prove that it would never be particularly popular or useful. They knew (correctly) that the general public did not enjoy using computers. They knew that turning the internet into the promised universal medium for trade and communication would require mind-boggling amounts of money and effort and the full cooperation of numerous set-in-their-ways corporations.

But they were wholly uninformed about the only fact that was relevant. They had not caught the bug so did not know just how compelling the World Wide Web was. They did not know it had the power to convert a hostile public into avid computer users. They did not hear the rising din of millions of keyboards. They did not know the Internet was a juggernaught before which all of their well-reasoned objections were as naught.

They were not liars, frauds, quacks, impostors, phonies, or shams. They were misinformed or ill-informed.


In a lecture room, bluffing;
in a pub, blagging;
when it's to boost yourself, it's bragging.
In the electronic age it's blogging.

Three of these words occur in this blogspot entry: http://perpetual-lab.blogspot.co.uk/2006/06/blog-blag-brag_08.html

  • 3
    Perhaps I am missing a joke, but blogging does not belong in your list. Nov 19, 2015 at 6:56
  • 2
    @SpehroPefhany you show good taste by refusing to acknowledge facetiousness; it ranks lower than sarcasm. But if all the blogs that you have come across are well-informed, and free of bluff and blag you are fortunate.
    – Hugh
    Nov 19, 2015 at 12:31

I think the most apt term here is "humbug":

Definition from dictionary.com


  1. something intended to delude or deceive.

  2. the quality of falseness or deception.

  3. a person who is not what he or she claims or pretends to be; impostor.

  4. something devoid of sense or meaning; nonsense: a humbug of technical jargon.

  5. British. a variety of hard mint candy.

verb (used with object), humbugged, humbugging.

  1. to impose upon by humbug or false pretense; delude; deceive. verb (used without object), humbugged, humbugging.

  2. to practice humbug.


  1. (used as an expletive to express rejection of something as being completely untrue or nonsensical.)

Note particularly definition 3.


I might call him an Fraud, especially if he were putting his so called knowledge to use in order to separate me from money, or requires compensation for his "experience"


Some of the options not yet suggested:

  1. phony:

Fraudulent, deceitful, or dishonest: a phony expert in investing.

(The Free Dictionary)

  1. sham:

someone who deceives people by pretending to be a particular kind of person, to have a particular skill, etc.


  1. impostor:

one who makes false claims of identity or expertise


  1. quacksalver:

A quack or charlatan (archaic).


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