[ dih-fin-i-tiv ]
/ dɪˈfɪn ɪ tɪv /
Save This Word!


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. providing the environment in which a fully developed parasite is able to reproduce, as is provided by a definitive host.


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).



Apostrophes can be tricky; prove you know the difference between it’s and its in this crafty quiz!
Question 1 of 12
On the farm, the feed for chicks is significantly different from the roosters’; ______ not even comparable.

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)
definite, definitive
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for definitive

/ (dɪˈfɪnɪtɪv) /


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
definitively, 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
Hate Typos? Get Grammar Coach