Literally, אדני 'ădonāy has become “as an enemy.”
Related Commentaries of Lamentations 2:5
Lamentations 2:5
5 The Lord was as an enemy: he hath swallowed up Israel, he hath swallowed up all her palaces: he hath destroyed his strong holds, and hath increased in the daughter of Judah mourning and lamentation.