Means the exact opposite of wonderful. Seeing as how fuck has become a fad to say when something bad happens, if you combine the two its like saying fuck x10
"Dude i totally spaced and forgot to go to work. Wonderfuk."
"I forgot to feed my moms favorite bird, now im wonderfuked"
"I forgot to feed my moms favorite bird, now im wonderfuked"
by Timmytickletits September 17, 2011