WordWeb Online

1. Clearly defined or formulated
   "the plain and definitive language of the laws"
   - unequivocal
    
2. Of recognized authority or excellence
   "the definitive work on Greece"
   - authoritative, classical, classic
    
3. Supplying or being a final or conclusive settlement
   "a definitive verdict"
   - determinate

See also: conclusive, explicit, expressed, standard

Encyclopedia: Definitive