His anger clouded his judgment, leading to a poor choice.

clouded 是动词 cloud 的过去式。cloud 本义是"云"，在这里用作动词，表示"使模糊、使蒙蔽"，就像云朵遮挡视线一样。clouded judgment 指的是"被情绪影响而变得不清晰的判断力"。