大敌的英文：
archenemy; formidable enemy

参考例句：

Frost is an enemy of flowers.
霜冻是花卉的大敌。

Man has not a greater enemy than himself
人之大敌,自己而已

Procrastination is the thief of time.
因循拖延是时间的大敌;拖延就是浪费时间。

Nowadays, the watery moats which were Venice's protection have become its enemy
曾经保护威尼斯的护城河现今却成了它的大敌。

"The greatest friend of truth is time, her great enemy is prejudice, and her constant companion is humility."
"时间为真理之挚友偏见为真理知大敌,谦虚则为真理恒久之伴侣"

Well-favored, stately, swift, unwearied, puissant, gigantic, he is still the foe of wisdom, the scourge of mortals
他得天独厚，威严、敏捷、久战不倦、孔武有力、魁梧壮伟。至今，他还是智慧的大敌，人类的祸灾。

archenemy是什么意思：
n. 撒旦；死敌，主要敌人

He actually made friends with his archenemy, Doune.
他竟同自己的死敌唐恩结成了朋友。

formidable是什么意思：
adj. 强大的，可怕的，难对付的；令人敬畏的

The assistants raised a formidable hurrah.
助手们发出了一片震天的欢呼声。

He fronted a formidable band of fighters.
他率领着一队可畏的斗士。

There are formidable problems associated with the practical utilization of solar energy.
有一些令人生畏的难题与太阳能的实际应用联系在一起。

A new and formidable danger menaced the western frontier
一个新的可怕的危险威胁着西部边界

This woman was too young to be on the formidable level of wifehood
这个女人太年轻，还未达到作一位贤惠的妻子的标准。