"What a fearful thing it is that any language "should possess a word to express the pleasure which men feel at the "calamities of others; for the existence of the word bears testimony "to the existence of the thing! And yet such in more languages "than one may be found!" In the Greek the word is ἐπιχαιρεκακία, and in German we have Schadenfreude, Schadenlust, and Schadenfroheit, all meaning the same thing."
- Archbishop Trench, On the Study of Words (1851)

or, in a (slightly) broader sense, to gloat..