Abbreviation of the very popular Polish saying "Co za ciul" which generally means "What an asshole". Usually said in a very sarcastic and degrading tone within a group of friends when having a big laugh of someone who did something extremely stupid.
*Primo class jerk in a suit falling off the stairs and wiping a pile of mudd with his face*
(Class) - Co za ciul !!! CZC
*Everyone laughing hard*