/,ʌnə'seɪləbl; ,ʌnə`seləbl/
adj
(a) that cannot be attacked or conquered 攻不破的; 不可征服的:an unassailable stronghold, fortress, etc 攻不破的堡垒、要塞等
* Liverpool have (built up) an unassailable lead at the top of the First Division. 利物浦队高居甲级队之首, 所向无敌.
(b) (fig 比喻) that cannot be questioned or refuted 不容置疑的; 无可辩驳的
*Her position/argument is unassailable. 她的立场[论点]是无懈可击的.

adj formal
not able to be criticized, made weaker, or beaten
　an unassailable argument
　The party's position looked unassailable .
　The result gave the team an unassailable lead .