Several of her patients have made allegations of professional misconduct against her.

allegations 是名词 allegation 的复数形式，allegation 来自动词 allege（声称、指控），指"未经证实的指控或断言"。 professional misconduct 是固定搭配，professional 指"职业的"，misconduct 由前缀 mis-（表示"错误"）和 conduct（行为）组成，合起来指"职业上的不当行为"。