Thundershock does not exist as a word in the English language.
It is the name given to a Pokemon character that shoots lightning bolts and paralyzes opponents.
However, the name doesn't make any sense, since thunder is the sound that lightning makes. The thunder is produced from electricity (the lightning) but does not produce any electricity itself.
"Thunderbolt" would make more sense, because that is actually the flash that occurs with lightning, and also refers to a sudden emotional shock.