presumptive
/prɪˈzʌmptɪv; prɪ`zʌmptɪv/ adj
(fml esp law 文, 尤用於法律)
(a) based on reasonable belief 基於合理之推测的; 推定的
presumptive evidence 推定的证据.
(b) probable 可能的; 假定的
the presumptive heir/the heir presumptive, ie the person who will inherit the throne unless sb with a stronger claim is born 假定继承人（除非有更具继承权资格的人出生, 否则即由其继承王位）.