See Part I for an explanation of what we're doing here.
Felicity Carter, of Neustadt/Wein, Germany, writes: "We've got the word schadenfreude for taking pleasure in the misfortune of others. But where is the word for when the fortune of others makes you miserable -- for instance, when your rival succeeds. As Gore Vidal said, 'Whenever a friend succeeds, a little something in me dies.'"
Ammon Shea replies: I'm always amazed at how easy it is to overlook the obvious gems of our language. This is a great question, and I knew I'd seen this exact word somewhere. So I started digging through several years of notes, looking for the appropriate obscure term that would match this definition. I came across stomaching (feeling or cherishing indignation or bitterness), and hindermate (a companion who is a hindrance), but these words are only in the same general area.
Ingrudge (secret enmity) is a bit closer, as is Job's comforter (a person who aggravates distress under the guise of administering comfort), but neither of these has the core meaning that we're looking for: the sense of discontent at the success of another.
And then I finally decided to check the words that we all know, just to see if perhaps one of them had an earlier meaning of which I was unaware that might match. The first word I looked up, envious, is defined in the OED as 'vexed or discontented at the good fortune or qualities of another.' So there you have it, although I'm still partial to grudgement (envy, resentment).