pronounced: es-tee-ef-you-em-ef-er. a way of saying: shut the fuck up mother fucker.
used in texting, short hand messages, or even in a stressful situation; if someone insults me I'm like, "STFU MF-ER!"
by kkbby June 19, 2009
Emails are sent from firstname.lastname@example.org. We'll never spam you.×