For some time now, the widespread misuse of the word disinterested has been a bee in the bonnet of every poor soul who can’t seem to stop themselves from getting worked up about lexical minutiae.
As any one of those aforementioned pedants will tell you (probably exasperatedly), disinterested doesn’t just mean uninterested. The latter describes someone who is quite literally not interested in a given thing. If Friends fan theories bore you to tears, you’re likely uninterested in hearing why some people believe Rachel dreamed the entire series. If you’ve never listened to the Hamilton soundtrack and have no plans to do so in the future, you’re likely uninterested in reading about the explanations behind a bunch of Hamilton lyrics.
Disinterested, meanwhile, usually describes someone who has no vested interest in something, or no particular interest in one side over another; i.e. impartial or unbiased. A judge, for example, shouldn’t be uninterested in hearing both sides of a case—but they should be disinterested. If you’re a disinterested MLB umpire, you don’t let the fact that you loved the Yankees as a kid cause you to favor them when making calls.
Or, at least, that’s what the consensus is among language prescriptivists today. As Merriam-Webster explains, the blurry line between these two words has existed for centuries; and when they first arrived on the scene in the early 17th century, their definitions were actually reversed. Walter Montagu used uninterested to mean unbiased more than once in his masque The Shepheard’s Paradise, first performed at court in England in 1633. In it, uninterested modifies “prayers,” “faith,” and “a Counsellor” at different moments in the drama. Around that same time, John Donne used disinterested to mean uninterested.
These days, you can get your point across if you pull a Donne—even Merriam-Webster recognizes that disinterested can mean “not interested.” But if your priority is appeasing the grammar sticklers in your life, you might not want to.