(Without looking at eta's link which I'm far too lazy to do...)
Does it have something to do with the Hunting of the Snark perhaps? Probably not, I think it's just a word that sounds like snappy and sharky or similar nasty referents.
Parichareia, according to Rabelais, is a term meaning destructive excess of joy. Has anyone ever seen this word before? I'm having a hard time finding much about it.