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.Used on Usenetnewsgroup alt.syschef.recovery as substitute for "fuck" and became more main-stream after the Communications Decency Act.(1998-03-06)