Does there exist a subset of words which can be used to define all others?

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?

Solution 1:

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):

Substantives: I, YOU, SOMEONE, PEOPLE, SOMETHING~THING, BODY
Relational substantives: KIND, PART
Determiners: THIS, THE SAME, OTHER~ELSE
Quantifiers: ONE, TWO, SOME, ALL, MUCH~MANY, LITTLE~FEW
Evaluators: GOOD, BAD
Descriptors: BIG, SMALL
Mental predicates: THINK, KNOW, WANT, FEEL, SEE, HEAR
Speech: SAY, WORDS, TRUE
Actions, events, movement: DO, HAPPEN, MOVE
Location, existence, specification: BE (SOMEWHERE), THERE IS, BE (SOMEONE/SOMETHING)
Possession (SOMETHING) IS (SOMEONE'S)
Life and death: LIVE, DIE
Time: WHEN~TIME, NOW, BEFORE, AFTER, A LONG TIME, A SHORT TIME, FOR SOME TIME, MOMENT
Space: WHERE~PLACE, HERE, ABOVE, BELOW, FAR, NEAR, SIDE, INSIDE, TOUCH
Logical concepts: NOT, MAYBE, CAN, BECAUSE, IF
Intensifier, augmentor: VERY, MORE
Similarity: LIKE~AS~WAY

Solution 2:

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:

table

: 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.

Answer

Your question is either unanswerable or trivial.

Either

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.

or

2. 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.