V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

FSCK
       File System Consistency checK (Unix)


The Free On-line Dictionary of Computing (30 December 2018):

fsck

   1.  file system check.  The Unix program
   that checks a file system for internal consistency and bad
   blocks etc. and can repair some faults.

   fsck is often used after a crash when the file system has
   been left in an inconsistent state, e.g. due to incomplete
   flushing of buffers.

   (1998-03-06)

   2.  Used on Usenet newsgroup alt.sysadmin.recovery
   as substitute for "fuck" and became more main-stream after the
   Communications Decency Act.

   (1998-03-06)