引起恐惧
... [robber] 抢夺他人财物的人 [formidable enemy;formidable foe] 引起恐惧、恐怖或忧虑的敌人 [powerful enemy;powerful foe] 力量强大的敌人 ...
大敌
... a formidable appearance look prospect 可怕的外表 formidable enemy; archenemy 大敌 formidable looking code 似可畏码 ...
当发怒或受惊吓时,黑熊会变成可怕的对手。
The self is in a sense the formidable enemy of a person.在某种意义上,自我才是自我的最大敌人。
Perhaps the builders had heard of a new, formidable enemy that they had not.也许创建者听说了他们不知道的新的、强大的敌人。