F5

Commonly accepted as the strongest tornado possible. According to Thomas Schlatter, the Fujita scale goes all the way up to F-12, which is winds the speed of sound. The article was actually written in Fune 1986 and was cited in the Jan/Feb 98 issue of the same periodical. Since before the original article was written in 1986, there has never been a documented tornado of F-6 or above, and the author states it's not likely to happen.

James R. McDonald includes a table of Fujita levels and wind speeds. F-6 and above is labled as "inconcievable damage". Wind speed are as follows (in miles per hour):
F-6 319-379
F-7 380-445
F-8 446-513
F-9 514-585
F-10 586-659
F-11 660-735
F-12 736 and above
note: The speed of sound at -3ºC is 736 miles per hour.

Works Cited

McDonald, James R. "T. THEODORE FUJITA: HIS CONTRIBUTION TO TORNADO KNOWLEDGE THROUGH DAMAGE DOCUMENTATION AND THE FUJITA SCALE." Bulletin of the American Meteorological Society; Jan2001, Vol. 82 Issue 1, p63-72

Schlatter, Thomas. "F6 Tornadoes." Weatherwise; Jan/Feb98, Vol. 51 Issue 1, p28

by Mike February 5, 2005

F5-ing

When Reloading, Refreshing, To Refresh, Time of the month, So on so forth(hehe).

"This is taking to long, I'm F5-ing this shit!"

by YouDidntKnowWhatItMeantDidYou July 22, 2014

F5

An F5 is the category assigned to the most powerful of tornadoes. The "F" refers to "Fujita," Because it's the Fujita scale that's used to measure how violent tornadoes can get. Ratings range from F1 to F5. F1 means a rather weak twister, about 70 to 90 m.p.h., and an F5 is the mother of all dust devils. While F2s, F3s and F4s are also really dangerous (F4s are almost as destructive), they are popcorn farts compared to F5s. If there's an F5 in your vicinity,
A) squat down
B) place your head firmly between your legs
C) kiss your ass goodbye.

That F5 twister lifted my house off its foundation, spat it out in splinters like a projectile vomiting vacuum cleaner, impaled my dog onto the neighbor's weathervane, sucked all the sewage out of the water treatment plant, and now it's raining peanuts, second hand toilet paper, fermenting turds and aborted puppies. But what a hell of a blowjob! WOOOOHOOOO!!!!!!

by grap December 19, 2008

F5

v. 1 To refresh yourself, like if you've been daydreaming during a meeting.
v. 2 To wake up.

Origin comes comes from the use of F5 as a "Refresh" key for MS Windows applications.

1.
Frank: Greg, what did you think of Tom's suggestion.
Greg: (Daydreaming) Huh? Wha?
Tom: F5, dude!

2.
I can't really F5 until my second cuppajava.

by Leif June 10, 2006

f5 this

the act of pressing the f5 key on your computer so the page refreshes

gayboy: do you have anymore replies on Y!A?
bigirl: i dunno i need to f5 this shit.

by bigirl2009 June 16, 2009

f5ing

The act of repeatedly pressing the f5 key to reload a web page in anticipation of an update. Most commonly associated with social aggregate sites like 4chan and Reddit.

1: Man, you look tired this morning.
2: Yeah, I was up all night f5ing 4chan.

by reenact12321 January 2, 2012

f5

WWE Superstar Brock Lesnar's finisher.

Brock Lesnar hits Kurt Angle with the F5 and gets the pin to retain his WWE Undisputed Heavyweight Championship!

by SmackAhoe July 24, 2003