adj. 1 (of an answer, treaty, verdict, etc.) decisive, unconditional, final. °Often confused in this sense with definite, which does not have connotations of authority and conclusiveness: a definite no is a firm refusal, whereas a definitive no is an authoritative judgement or decision that something is not the case. 2 (of an edition of a book etc.) most authoritative. 3 Philately (of a series of stamps) for permanent use, not commemorative etc. definitively adv.
[ ME f. OF definitif -ive f. L definitivus (as DEFINE) ]