Disinterest means free from bias or prejudice; uninterest means a lack of interest, concern, or attention. Thus His poor vocabulary shows clear uninterest in reading, A good jury must always exhibit disinterest in a trial. The past-participial adjective disinterested takes a more nuanced meaning than its root form—it indicates not only a lack of bias but also a lack of personal gain. The past-participial adjective uninterested retains the same meaning as its root form. Both adjectives appear more frequently in modern use than their noun equivalents.