vulnerable to attack; not impregnable 可攻克的,易受攻击的 the fort's pregnable approaches. 堡垒易受攻击的入口处。
语源
late Middle English: from Old French prenable, literally takable', from Latin prehendere 'seize'. The g was sometimes written in French, perhaps indicating palatal n, but has come to be pronounced as a separate sound in English