A fork of Rural Dictionary
Short for "shut your fat mouth".
CrZyLdy77: omg! i just got tix to see fall out boy!1! MUNKYchick12: no way! SYFM!!! CrZyLdy77: no, rlly!!!!!!!!!1!
Shut yer fuckin mouth. much similar to stfu
syfm n00b i pwn you