If you describe something such as a reaction, treatment, or result as undeserved, you mean that the person who experiences it has not earned it and should not really have it.
例句
Douglas has an undeserved reputation for being dull and dry...道格拉斯呆板無趣的名聲并不副實。Jim's treatment was harsh and undeserved.吉姆受到了不應有的苛刻待遇。