most reliable or complete, as of a text, author, criticism, study, or the like: the definitive biography of Andrew Jackson.
serving to define, fix, or specify definitely: to clarify with a definitive statement.
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.
Biology. fully developed or formed; complete.


a defining or limiting word, as an article, a demonstrative, or the like.
Philately. a stamp that is a regular issue and is usually on sale for an extended period of time.Compare commemorative(def 2).

Origin of definitive

1350–1400; Middle English < Old French < Latin dēfīnītīvus, equivalent to dēfīnīt(us) (see definite) + -īvus -ive
Related formsde·fin·i·tive·ly, adverbde·fin·i·tive·ness, nounnon·de·fin·i·tive, adjectivenon·de·fin·i·tive·ly, adverbnon·de·fin·i·tive·ness, nounun·de·fin·i·tive, adjectiveun·de·fin·i·tive·ly, adverbun·de·fin·i·tive·ness, noun
Can be confuseddefinite definitive

Synonyms for definitive Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for definitive

Contemporary Examples of definitive

Historical Examples of definitive

British Dictionary definitions for definitive



serving to decide or settle finally; conclusive
most reliable, complete, or authoritativethe definitive reading of a text
serving to define or outline
zoology fully developed; completethe definitive form of a parasite
  1. (of postage stamps) permanently on sale
  2. (as noun)a definitive postage stamp


grammar a word indicating specificity of reference, such as the definite article or a demonstrative adjective or pronoun
Derived Formsdefinitively, adverbdefinitiveness, noun
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

Word Origin and History for definitive

late 14c., from Old French definitif (12c.), from Latin definitivus "explanatory, definitive," from past participle stem of definire (see define). Related: Definitively.

Online Etymology Dictionary, © 2010 Douglas Harper