Schadenfreude is pleasure derived from the misfortune of others. It is a feeling of joy, or an expression of pleasure or self-satisfaction, that comes from learning of another's troubles or failures.
Shadenfreude differs from sadism in that Sadism is specifically enjoying the physical pain or humiliation of others, rather than the misfortune of others.
The Engolish term Epicharikaky is a direct equivalent, and was considered to be a sin by the medieval church.