WTF

WTF  is a shorthand expression for “what the f**k?” which is commonly used in a wide range of contexts in online conversations, most prominently as an intensive (i.e. “WTF?!”) or an interrogative (i.e. "WTF do you mean?).

Origin
The online usage of its acronym  WTF  can be traced to Usenet newsgroups in the 1980s, with the earliest iteration in a discussion thread about The Grateful Dead, which was posted via net.music.gdead by Dick Dunn on October 31st, 1985: BUT, can anyone shed even a little light on the lyrics of China Cat Sunflower? I’ve READ them; I know what all the words are. I still say, “WTF, over?” Someone’s playing with our heads on this one, but what’s all the word stew?

Etymology
The expression “what the f**k” has its roots in colloquial American English, with the earliest known iteration in print found in the 1983 fiction  Handling Sin  by American author Michael Malone. Gates hopped out of the cab. “What the f**k…” He looked at the teenager.“Sh*t a brick. It’s the kid from the department store! Kure Beach, right?” Various English word reference sites have cited U.S. military slang as the origin of the acronym, sometimes euphemized in NATO phonetic alphabet as “Whiskey Tango Foxtrot,” although it remains unattributed. According to Google Books, the phrase “what the f**k” (shown below, left) began appearing in print publications at the beginning of the 1960s while its acronym “WTF” (shown below, right) saw a notable increase in number of mentions starting in 1975, shortly after the foundation of World Taekwondo Federation (WTF) in 1973.

Spread
Throughout the 1990s, the usage of phrase became increasingly commonplace in Usenet newsgroups and internet chatrooms with the emergence of word filters and censorship of expletives in highly-trafficked chatrooms and message boards. The earliest Urban Dictionary definition of “WTF” was submitted by an anonymous user on December 10th, 1999: What the f**k? Use it in place of expletives, a more polite alternative. As of July 2012, there are more than 175 Urban Dictionary entries for the acronym, although the top voted definition refers to the World Taekwondo Federation, which is also abbreviated as “WTF.”