Pronunciation: (di-fin'i-tiv),[key] —adj. 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. 4. Biol.fully developed or formed; complete.
—n. 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. Cf. commemorative (def. 2).