A definition is a statement of the meaning of a term (a word, phrase, or other set of symbols). Definitions can be classified into two large categories, intensional definitions (which define a thing by the properties necessary for its identity) and extensional definitions (which proceed by selecting the things belonging to the extension of a term—i.e., the set of things the term describes).[1]

Concise Definition

A definition is the act of establishing or describing what a word or concept means, typically by stating the essential qualities or characteristics that distinguish it from others.

1. Etymology

The word "definition" is derived from the Latin definitio, from definire "limit, determine," from de- (expressing reversal or removal) + finire "end, limit".[2] The sense of "defining words" is attested from the mid-14th century, while the sense of "defining boundaries" appears later.

2. General Definition

In a general sense, a definition is a statement of the meaning of a term. Terms can include words, phrases, and other sets of symbols. To define a term, a definer states in a host language what meaning is in the definiendum.[3]

The term being defined is called the definiendum (from Latin, "that which is to be defined"), and the term or phrase used to define it is called the definiens ("that which defines").[4]

AI Context: In computational semantics and machine learning, definitions play a critical role in knowledge graphs and ontologies. Aevum's AI engine uses definitions to resolve ambiguity and map relationships between concepts across 140+ languages.

3. Types of Definitions

Philosophers and logicians distinguish several types of definitions, each serving different purposes in discourse and inquiry.[5]

3.1 Stipulative

A stipulative definition assigns meaning to a word or phrase, either using existing terms with new uses or strings of letters with no use as terms so far. For example, a scientist may stipulate the definition of a new particle. Stipulative definitions cannot be true or false; they are proposals.[6]

3.2 Lexical

A lexical definition reports the meaning of a word as it is currently used. These definitions are descriptive and can be evaluated as true or false based on linguistic usage. Dictionaries primarily provide lexical definitions.[7]

3.3 Precising

A precising definition reduces the vagueness of a concept for a particular purpose. For example, defining "adult" as "a person aged 21 or older" in a legal context. These definitions aim to clarify boundaries.[8]

3.4 Theoretical

A theoretical definition proposes a theoretical account of what a thing is. For example, defining "water" as "H₂O" is a theoretical definition that goes beyond linguistic usage to make a claim about the nature of reality.[9]

Type Purpose Truth-Value Example
Stipulative Assign new meaning N/A "A blorg is a red sphere."
Lexical Report usage True/False "Cat: a small domesticated feline."
Precising Reduce vagueness Controversial "Poverty: income below $2/day."
Theoretical Explain nature True/False "Heat: kinetic energy of particles."

4. Formal Logic

In formal logic, definitions are often expressed using the genus differentia method, where a concept is defined by identifying the broader class (genus) it belongs to and the specific characteristics (differentia) that distinguish it from other members of that class.[10]

For example, a "square" can be defined as a rectangle (genus) with four equal sides (differentia). This method is foundational in Aristotelian logic and remains widely used in philosophical analysis and legal drafting.[11]

5. Aevum AI Methodology

At Aevum Encyclopedia, definitions are enhanced through a multi-layered AI verification process:[12]

  • Semantic Parsing: Natural language definitions are parsed to extract logical structure and relationships.
  • Cross-lingual Alignment: Definitions are mapped across languages to ensure conceptual consistency.
  • Source Triangulation: AI cross-references definitions against academic databases, peer-reviewed journals, and historical texts.
  • Dynamic Updating: Definitions evolve as new research emerges, with version control tracking changes.

This approach ensures that Aevum definitions are not only linguistically accurate but also epistemologically robust, meeting the needs of researchers, students, and curious minds worldwide.[13]

6. See Also

7. References

  1. Hirsch, E. D. (1984). The Dictionary of Critical Terms. University of Chicago Press.
  2. "Definition." Oxford English Dictionary. Oxford University Press.
  3. Cohn, W. (2010). "Definition." Internet Encyclopedia of Philosophy.
  4. Hurley, P. J. (2009). A Concise Introduction to Logic. Cengage Learning.
  5. Sainsbury, R. M. (1995). Concepts. Blackwell Publishing.
  6. Stein, S. (2004). "Defining Terms." Practical Logic.
  7. Crane, T. (2013). Metaphysics. Palgrave Macmillan.
  8. Black, M. (1954). "The Analysis of Definition." Philosophical Review, 63(4), 380-395.
  9. Putnam, H. (1975). "The Meaning of 'Meaning'." Minnesota Studies in the Philosophy of Science, Vol. 7.
  10. Aristotle. Categories. Translated by J. Lear.
  11. Kneale, W., & Kneale, M. (1962). The Development of Logic. Oxford University Press.
  12. Aevum Research Lab. (2023). "AI-Enhanced Semantic Verification in Knowledge Bases." Aevum Technical Journal, 4(2).
  13. Aevum Editorial Board. (2024). "Editorial Guidelines for Definition Entries." Aevum Encyclopedia.