Well, thanks to Dr Bill, I've found the Greek word that epicaricacy is based on: epikhairekakeo 'to rejoice in the misfortune of others' with epikhairekakia as the noun. I'd still like to known who coined the word in English and where it was used. To see if Bailey or his source misspelled it. Anyway, epichaerecacous would make a nice adjective and epichaerecaky might be OK for the noun. The Greek erb epichairo 'to rejoice in something (w. dat.) malignantly' is interesting.