A mild Finnish swear word with roots in the LAN party scene. Used either to insult someone personally or to insult a group of people (mursut). The literal meaning of mursu is walrus.
Mursu perkele! (Why... you damn walrus!)
The cool fun pop term for a well publicized "Murder-Suicide". coined by 'ThunderChunk69'
Man, I was hoping Benniffer would have had a MurSu to end it all!