It can be "unbiased", "indifferent". Granted, in the context of a "disinterested person", the answer would be unbiased. But the question simply says "Disinterested". Without context how do we identify the best suited meaning ?
Hi Aravind, disinterested is usually used for impartial while uninterested is used for not interested. At times, as you pointed out, disinterested is incorrectly used for not interested to the point that the distinction between the two terms is no longer considered a hard and fast rule. Nevertheless, the correct mean of disinterested is impartial and that of uninterested is not interested.