decisive
1. [ adjective ] determining or having the power to determine an outcome
Examples:

"cast the decisive vote" "two factors had a decisive influence"

Related terms: indecisive fateful conclusive crucial peremptory crucial conclusive
2. [ adjective ] unmistakable
Examples:

"had a decisive lead in the polls"

Related terms: definite
3. [ adjective ] characterized by decision and firmness
Examples:

"an able an decisive young woman" "we needed decisive leadership" "she gave him a decisive answer"

Related terms: indecisive unhesitating resolute
4. [ adjective ] forming or having the nature of a turning point or crisis
Synonyms: critical
Examples:

"a critical point in the campaign" "the critical test"

Related terms: crucial
Similar spelling:   decisively