Dictionary.com
Thesaurus.com
Synonyms

definitive

American  
[dih-fin-i-tiv] / dɪˈfɪn ɪ tɪv /

adjective

  1. most reliable or complete, as of a text, author, criticism, study, or the like.

    the definitive biography of Andrew Jackson.

  2. serving to define, fix, or specify definitely.

    to clarify with a definitive statement.

  3. having its fixed and final form; providing a solution or final answer; satisfying all criteria.

    the definitive treatment for an infection; a definitive answer to a dilemma.

    Synonyms:
    supreme, ultimate, absolute, complete
  4. Biology. providing the environment in which a fully developed parasite is able to reproduce, as is provided by a definitive host.


noun

  1. a defining or limiting word, as an article, a demonstrative, or the like.

  2. Philately. a stamp that is a regular issue and is usually on sale for an extended period of time.

definitive British  
/ dɪˈfɪnɪtɪv /

adjective

  1. serving to decide or settle finally; conclusive

  2. most reliable, complete, or authoritative

    the definitive reading of a text

  3. serving to define or outline

  4. zoology fully developed; complete

    the definitive form of a parasite

    1. (of postage stamps) permanently on sale

    2. (as noun) a definitive postage stamp

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

  1. grammar a word indicating specificity of reference, such as the definite article or a demonstrative adjective or pronoun

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Derived Forms

Etymology

Origin of definitive

First recorded in 1350–1400; Middle English, from Old French, from Latin dēfīnītīvus, equivalent to dēfīnīt(us) ( see definite) + -īvus adjective suffix ( see -ive)

Explanation

A definitive answer is a final one. A definitive decision by a court of law is one that will not be changed. A definitive translation is one everyone turns to as correct. Definitive means authoritative, conclusive, final. Be careful not to confuse definitive with definite. Definite means clearly defined. You can have a definite opinion that JFK could not have been assassinated by a lone gunman, but the definitive interpretation remains that of the Warren Commission Report, which held there was only one.

Keep Reading on Vocabulary.com

Vocabulary lists containing definitive

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“I know this is traumatic for the whole community. Now that we have a definitive result, we’ll talk with the counselors, and we’re gonna have some hard conversations,” he said.

From Los Angeles Times • Jun. 5, 2026

“If we wait for definitive evidence that high inflation has become embedded in the economy, it may require larger policy adjustments, at greater cost,” Hammack adds.

From Barron's • Jun. 2, 2026

And while that relentless sanguinity might be unrealistic, it’s perfect for a film that ostensibly exists as the definitive last word in a legacy.

From Salon • Jun. 2, 2026

Salesforce’s mixed April-quarter results didn’t give investors a definitive answer regarding whether or not the company could buck the software selloff and remain competitive in an AI-first market.

From MarketWatch • May 27, 2026

Howard and Smith much preferred that the horses meet in a definitive one-on-one match, in which no other horses could cause interference or otherwise affect the outcome.

From "Seabiscuit: An American Legend" by Laura Hillenbrand

Vocabulary.com logo
by dictionary.com

Look it up. Learn it forever.

Remember "definitive" for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.

Take me to Vocabulary.com