1550s, from Latin definitus "defined, bounded, limited," past participle of definire (see define). Definite means "defined, clear, precise, unmistakable;" definitive means "having the character of finality."
1. Her Royal Highness has definite views about most things.
2. When you came away you made a definite effort to mix.
3. Mary is very definite about this.
4. In a double-blind trial, there were definite improvements.