# ontology

Pronunciation: say "on-TOL-uh-jee" US /ɑnˈtɑləd͡ʒi/, UK /ɒnˈtɒləd͡ʒi/

## Noun

1. The branch of metaphysics concerned with the nature and essential features of being and of the things that exist; the study of being as such.
   - Simple: The part of philosophy that asks what it means for something to exist and what kinds of things exist.
   - _His real concern was with ontology: what it is for anything, and above all a person, to be._
   - _The seminar begins with ontology before it turns to questions of knowledge and value._
2. A structured model of the concepts or entities within a domain, organized by the relationships between them.
   - Simple: A model of the ideas and things in a subject area and how they are linked to each other.
   - _The hospital built an ontology of diseases, symptoms, and treatments so its software could link patient records._
   - _Shared ontologies let different labs describe genes and proteins in the same terms._
3. The kinds of things that a particular worldview, theory, or philosopher holds to exist, and how they relate to one another.
   - Simple: The set of things a particular theory or thinker believes really exist.
   - _A strict materialist's ontology has room for particles and fields but none for souls._
   - _The novel's ontology, crowded with gods, spirits, and talking rivers, is never questioned by its characters._

## Other meanings

- (noun) Stanisław Leśniewski's (1886–1939) system of logic, a calculus of names built on the word "is" as its basic sign.

## Origin

A learned borrowing from New Latin ontologia, coined in 1606 by Jacob Lorhard, from Ancient Greek ṓn, óntos ("being") + lógos ("account"); by surface analysis, onto- + -logy. Its first known English use is in Gideon Harvey's 1663 Archelogia philosophica nova, and the German philosopher Christian Wolff popularized it as a philosophical term.

Source: DictionaryAI, https://dictionaryai.com/define/ontology (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).