- Date Found: Beyond Time and the interwebs
- Used By: Channers, IRCers
STFU is an initialism for "Shut The F**k Up!"
Often used to tell someone who's being rather verbose to curtail their speaking. Also used to tell someone you find annoying to please be quiet. Often paired with GTFO.
- STFU N00b!
- Look, STFU and GTFO!