[Usenet; very common] Fucking, in the expletive sense (it refers to
the Unix filesystem-repair command
fsck8,
of which it can be said that if you have to use it at all you are having a
bad day). Originated on scary devil monastery and
the bofh.net newsgroups, but
became much more widespread following the passage of
CDA. Also occasionally seen in the variant
What the fsck?