All words in the dictionary are defined by using other words. Has there been any research that has traced these definitions down to a subset of the English language which can define the rest of it? I'm imagining there must be some sort of recursive definition between all the words in this set.

In other words, have we identified the smallest group of words that could explain everything in the dictionary?

  • I think it's recursive. Aug 23, 2015 at 18:01
  • 3
    The real problem here is that the answer changes with the degree of specificity desired in those definitions. See XKCD's explanation of the Saturn V rocket I bet Randall could provide some definition using on the most common ten hundred words.
    – Jim
    Aug 23, 2015 at 18:03
  • This question was partially inspired by the Up Goer Five. :) Aug 23, 2015 at 18:04
  • 2
    There may not be a smallest set -- that would be impossible to prove, given present knowledge -- but there certainly are plenty of finite covers available for the set of lexical items in a language. One such is Anna Wierzbicka and Cliff Goddard's Natural Semantic Metalanguage. Aug 23, 2015 at 18:21
  • 1
    All words are infinitely polysemous. There are few if any true synonyms. Words are what we use to code for real phenomena, but they are woefully inadequate. Even the whole 1 000 000+ word lexicon is inadequate. Aug 23, 2015 at 18:21

4 Answers 4


The Natural Semantic Metalanguage is a controversial linguistic theory which claims to be just that. The theory says that there is a set of words (currently about 65) called semantic primes, which are the base level concepts. All other concepts can be defined using them, and they themselves cannot be defined. Furthermore the theory says that these words are universal, being used in every language (though sometimes these semantic primes are words, sometimes affixes and sometimes phrases.) The list of primes is always a work in progress, but after over 40 years the users of NSM would claim that most of the have been borne out in research in dozens of languages.

This list of primes is (~ marks 'allolexes' where the same prime has different forms depending on context):

Relational substantives: KIND, PART
Evaluators: GOOD, BAD
Descriptors: BIG, SMALL
Mental predicates: THINK, KNOW, WANT, FEEL, SEE, HEAR
Actions, events, movement: DO, HAPPEN, MOVE
Location, existence, specification: BE (SOMEWHERE), THERE IS, BE (SOMEONE/SOMETHING)
Life and death: LIVE, DIE
Logical concepts: NOT, MAYBE, CAN, BECAUSE, IF
Intensifier, augmentor: VERY, MORE
Similarity: LIKE~AS~WAY


A language depends on common knowledge. For example it is impossible to describe a colour to someone who has been totally blind from birth. Ultimately all words must be defined in terms of concepts we already know.

We learn new words when we are young children by listening, observing and asking questions. In particular most nouns are learned by a child pointing and saying, "What's that?"

There is a problem with dictionaries. Take the following definition:


: a piece of furniture that has a flat top and one or more legs

: a piece of furniture with a flat surface that is designed to be used for a particular purpose

Merriam Webster

We can complain that some objects that have flat surfaces and are designed to be used for a particular purpose are not tables - for example a refrigerator.

We can also object that some tables have a very rough surface that is not level.


Your question is either unanswerable or trivial.


  1. You would have to specify a specific type of dictionary. For example are you allowing picture dictionaries? But then you would still have to specify more and more narrowly what precisely was allowed.


  1. You must specify a particular dictionary. In that case the answer is trivial. Simply count all the distinct words in its definitions and there you are.
  • You're absolutely right. As for your last two points, I'm more interested in the results of such research, so do there exist any conclusions for specific dictionaries or other limiting parameters? (I'm not criticizing your answer; it's excellent.) Aug 23, 2015 at 18:30
  • I agree with colors. Webster's definition is trying to emphasize that the flat surface is used for a particular purpose, like putting stuff on. It might be better defined as "A piece of furniture that is designed with a flat top used for a particular purpose." might be a better definition to eliminate refrigerators. Using top instead of surface also reduces the chance of the interpretation being bookshelves, (although I doubt they're eliminated). #2 isn't exactly trivial since you'd have to reduce it down to the distinct words, rather than ones which could be fully defined with other concepts.
    – Tonepoet
    Aug 23, 2015 at 18:39
  • 1
    @Tonepoet - The problem with defining worldly objects goes back at least to Plato. It is always possible to find an objection. Mathematicians side-step the problem by defining things in a very narrow and idealised way. Even then they don't always succeed. I don't understand your point about 'trivial'. I already stated that it needs the words to be distinct. These days, given the full text of a dictionary in computer-readable form, it would take a matter of minutes to produce such a list. Aug 23, 2015 at 18:48
  • We do have such scans incidentally. I recommend using The Century Dictionary and Cyclopedia as it is the largest dictionary fully in the public domain. My point is that the process of elimination would need to involve using these hypothetical elemental words in every possible combination until all words which can be defined as a composite of them are eliminated, like how water and its forms are not truly distinct from hydrogen and oxygen. This might require trying to write a complex thesis for each word with the most limited vocabulary possible.
    – Tonepoet
    Aug 23, 2015 at 20:17
  • It's an interesting idea. Take an existing dictionary and then minimise the number of distinct words needed over all the definitions. Unfortunately I think it would be both unreadable and pointless. Rather like having an online document that consisted mostly of hypertext links to other documents that also consisted mostly of hypertext. Aug 23, 2015 at 20:27

Surprisingly while trying to learn many languages, 'Is' seems to be expressed as 'is'.

to me this seems to indicate that much of what we know and how we understand our knowledge could be summarized by such simple words.

Also note that to describe the unknown in Latin seems to suffix the term 'Omne', however alone it is non descriptive, hence the context of a sentence is the only true way to determine an awareness of emotions that are then elicited by terms or phrases.

Finally looking at how one single word can be altered within the scope of in-flex without specific languages in mind yet abstractly broadened it would be accurate to asses a summary of Literature both classically and contemporarily only within the notion of that vocabularies context. Ergo each word needs other words to describe its impact otherwise all that would be left is influx, much as you could imagine a cave man grunting to convey messages makes a picture of the importance of other words; Im my opinion at least.

  • 2
    What do you mean with your first sentence?
    – Helmar
    Jul 29, 2017 at 8:51

Yes. Taking account of the fact that every set is a subset of itself, all the words in the dictionary is such a set.

I see no reason to think there is a unique smallest such set, so no to the other form of your question about the smallest such set.

  • This is not an answer, but a comment. Read the entire question, not just the title.
    – wythagoras
    Aug 23, 2015 at 17:36
  • 2
    Technically answers the question in the title, but not "have we identified the smallest group of words that could explain everything in the dictionary?" as outlined in the question itself. For instance, a quick browse through the "A"s shows the word "Abacination" which is never again used in the entire dictionary. From that I can conclude "Abacination" is NOT part of the smallest subset which can explain the English language. Aug 23, 2015 at 17:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.