ontology

noun

on·​tol·​o·​gy än-ˈtä-lə-jē How to pronounce ontology (audio)
1
: a branch of metaphysics concerned with the nature and relations of being
Ontology deals with abstract entities.
2
: a particular theory about the nature of being or the kinds of things that have existence
ontologist
än-ˈtä-lə-jist How to pronounce ontology (audio)
noun

Examples of ontology in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The ontology evolves as the business evolves. — Peter Bendor-Samuel, Forbes.com, 25 June 2026 Bleeding Edge thus marks Pynchon’s most overt confrontation with the collapse of ontology into information. — Literary Hub, 10 Dec. 2025 The work in that book was surreal and stealthily philosophical—its opening poem was a fifteen-page meditation on the ontology of Popeye the Sailor Man—but impersonal. — Alexandra Schwartz, New Yorker, 25 Aug. 2025 When gene ontology analysis was performed on the regions of the village dog genome that were enriched for wolf ancestral elements, the only significant functional category was the olfactory transduction pathway. — Ritsuko Kawai, Wired News, 25 Dec. 2025 See All Example Sentences for ontology

Word History

Etymology

New Latin ontologia, from ont- + -logia -logy

First Known Use

1663, in the meaning defined at sense 1

Time Traveler
The first known use of ontology was in 1663

Rhymes for ontology

See All Rhymes for ontology

Browse Nearby Words

ontologize
ontology
on top
See all Nearby Words

Cite this Entry

“Ontology.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ontology. Accessed 7 Jul. 2026.

Copy Citation

More from Merriam-Webster on ontology

Britannica.com: Encyclopedia article about ontology

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

Is that lie 'bald-faced' or 'bold-faced'?

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?

Commonly Misspelled Words

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)
See More

Popular in Wordplay

See More

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

One-Word Oxymorons: Bittersweet, Spendthrift, and More

Ten Words Ending with a Silent ‘T’

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

Is that lie 'bald-faced' or 'bold-faced'?

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
hangman letters and game
Hangman Lightning Round Figure out which word fits in the blanks.
See All