[dis.in.ter.est.ed] adj (ca. 1612) 1 a: not having the mind or feelings engaged: not interested "telling them in a ~ voice --Tom Wicker" "Introverted. Unsocial ... Disinterested in women --J. A. Brussel" b: no longer interested "husband and wife become ~ in each other --T. I. Rubin"
2: free from selfish motive or interest: unbiased "a ~ decision" "~ intellectual curiosity is the lifeblood of real civilization --G. M. Trevelyan" syn see indifferent -- dis.in.ter.est.ed.ly adv usage Disinterested and uninterested have a tangled history. Uninterested orig. meant impartial, but this sense fell into disuse during the 18th century. About the same time the original sense of disinterested also disappeared, with uninterested developing a new sense--the present meaning--to take its place. The original sense of uninterested is still out of use, but the original sense of disinterested revived in the early 20th century. The revival has since been under frequent attack as an illiteracy and a blurring or loss of a useful distinction. Actual usage shows otherwise. Sense
2. of disinterested is still its most frequent sense, esp. in edited prose; it shows no sign of vanishing. A careful writer may choose sense 1a of disinterested in preference to uninterested for emphasis "teaching the letters of the alphabet to her wiggling and supremely disinterested little daughter --C. L. Sulzberger" Further, disinterested has developed a sense (1b), perhaps influenced by sense 1 of the prefix dis-, that contrasts with uninterested "when I grow tired or disinterested in anything, I experience a disgust --Jack London (letter, 1914)" Still, use of senses 1a and 1b will incur the disapproval of some who may not fully appreciate the history of this word or the subtleties of its present use.