adjective/deθiˈsibo/
decisive; defining (e.g. a defining moment); crucial, critical, key, instrumental, vital; deciding, swing
“voto decisivo” — swing vote
Etymology tree Latin dēcīdō Proto-Indo-European *-wós Proto-Indo-European *-iHwósder. Latin -īvus Medieval Latin decīsīvusbor. Spanish decisivo Borrowed from Medieval Latin decīsīvus. Compare French décisif.