redoubt
noun [ C ] uk/rɪˈdaʊt/ us/rɪˈdaʊt/
formal（尤指即将消失或受到威胁的信仰或生活方式的）安全藏身处，堡垒，据点
something that holds or defends a belief or a way of life, especially one that is disappearing or threatened
He described British public schools as "the last redoubt of upper-class privilege". 他称英国私立公学为“上层阶级特权的最后堡垒”。
military specialized防御工事;掩体
a small, often hidden building in which soldiers can hide while they are fighting