Use 'disinterested' to describe fairness and lack of bias, especially in formal or professional contexts. A judge should remain disinterested when presiding over a case.
Pro Tip 2/3
Not Emotional Disinterest
'Disinterested' is not about a lack of emotion; it's about impartiality. As a disinterested mediator, she helped resolve the conflict.
Pro Tip 3/3
Not Apathetic
Avoid confusing 'disinterested' with 'uninterested'; the former is neutral, not apathetic. Despite his personal connections, he gave a disinterested opinion on the matter.