1) word used by Zahler in Scott Westerfeld book "The Last Days" (not to be confused with feculent) Words also used fool and fawesome. To break away from the mainstream and express his creativity Zahler puts the letter 'F' infront of adjectives. Or he simply might mean the definition below.
2) fucking exlent
1) RandomPerson: fexelent shoes; where'd you get 'em?