From Longman Dictionary of Contemporary Englishdefinitivede‧fin‧i‧tive /dɪˈfɪnətɪv/●くろまる○しろまる○しろまるAWL adjective1[usually before noun]BEST a definitive book, description etc is considered to be the best and cannot be improveddefinitive study/work/guide etcthe definitive study of Victorian railway stations2CHANGE/MAKE something DIFFERENTa definitive agreement, statement etc is one that will not be changeda definitive agreement to buy the company —definitively adverbExamples from the Corpusdefinitive• None can provide a definitiveanswer to the question of whom resources should be spent on.• She has written the definitive book on the poet Wordsworth.• This may be the definitive book on the Scarlatti trial.• However, definitivedecisions about such measures must rest with medically qualifiedpersonnel.• However, the design can be a useful, if not a definitive, indicator of a rug's origins.• Many people regard it as the definitiveinterpretation of 'War and Peace'.• Suppose, for sake of argument, that this is indeed the definitivelegalposition.• The definitivemovie on these two men whose courage reshaped a nationremains to be made.• He added that many market watchers had been hoping for some type of agreement or definitivenewsyesterday.• A definitive set of grammaticaltags does not exist.• His books may not be the most definitive works on the phenomenon they describe.definitive study/work/guide etc• Because it will be my definitive work.• The Black Book Of Communism is not a definitive work.• A later and quite definitive studyconducted by Miller between 1973 and 1978 bore this out.• This is not the definitive work of television.• This became the definitive work of the period.• His books may not be the most definitive works on the phenomenon they describe.• Halliwell's FilmGuide the definitive guide to the movies. 4.