Other forms: disinterests
Disinterest is a lack of curiosity or attachment, like your complete disinterest in your younger sister's scene-by-scene recap of the plot of her favorite cartoon.
One kind of disinterest is simply a lack of enthusiasm, like your disinterest in sports or local politics: you just don't care. Another kind of disinterest is more of a neutrality or impartiality. A mediator, judge, or negotiator needs this type of disinterest in order to hear two opposing viewpoints without prejudice. Disinterest comes from the prefix dis-, "lack of," and interest, from the Latin interresse, "to concern, make a difference, or be of importance."