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.
When Chris Mursch ( The total flamer that goes to brookfield east and wants to rub Mrs.Wagners hairy mangina) takes a dump then removes his ass hair from the steamer and places it on your upper lip while you are sleeping.
Breu II was taking a nap and when he woke up he was excited to see he had a mursch mustache places nice and firmly on his upper lip.