An acronym for 'what the fuck' often capitalized for emphasis. Commonly used in chatrooms by lazy chatters, video game channels by dueling gamers, in curse-free environments like business or schools, and by sailors on ship over intercom systems who don't want to be cited.
Meanings an variations:
what the fuck
who the fuck
when the fuck
where the fuck
whiskey tango foxtrot (military slang version)
"WTF ARE YOU DOING! WORST TANK EVER!"
Gamer to gamer
"wtf are you doing on the deck?"
"wtf was she wearing?"