凭险 píngxiǎn
[resort to strategically located place of difficult access] 凭据险要的地势
凭险抵抗
依据险要的地势。 《新唐书.卷一二六.卢怀慎传》:「边徼之地,夷夏杂处,凭险恃远,易扰而难安。」 唐.阎伯玙〈河桥赋〉:「凭险作固,夹咽喉之重关。」
英语 (to resist the enemy) relying on inaccessible territory