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 ) .

adjective

incomplete , inconclusive , inexact , interim , temporary , unreliable

adjective

absolute , actual , categorical , clear-cut , closing , complete , completing , concluding , conclusive , decisive , definite , determining , downright * , ending , exhaustive , express , final , finishing , flat out * , last , limiting , nailed down , perfect , plain , precise , real , reliable , settling , specific , straight out , terminal , terminating , ultimate , unambiguousnotes:definite means \'precise and unmistakable , \' \'clear , sharply delineated\'; definitive means \'final and conclusive , \' \'complete , ultimate\' - so a definitive example is a perfect example , authoritative , determinative , explicit