According to several websites for the video game
King of Fighters, the phrase Zanretsu
Ken translates to "Momentary Violence Fist".
(for example,
http://mai.rinoa.nu/kof/faqs/98takuma.txt)
The Japanese translation software I use does not list "ken" as meaning either momentary, violence, or fist. The closest translation I saw was "sword". However, Japanese games are notorious for having terrible English translations when they are brought to North
America.