Another version of posting 'first' on a blog or message board to gain fame. Murst is a combination of the word murse and first which mocks the murse (man purse) worn by Casey Serin the internet celebutard.
Murst was originated and made popular by Casey Serin haterz on the exurbannation.blogspot.com blog.
Credit given to poster Fear The Murse for creating this internet meme.
Murst! First! haha sukas! Got it again!