intractable problem. 2. A crucial piece of hardware that can't be
fixed or replaced if it breaks. 3. A tool that has been hacked
over by so many incompetent programmers that it has become an
unmaintainable tissue of hacks. 4. An out-of-control but
unkillable development effort. 5. An embarrassing bug that pops up
during a customer demo.

This term has other meanings in other technical cultures; among
experimental physicists and hardware engineers of various kinds it
seems to mean any random object of unknown purpose (similar to
hackish use of {frob}). It has also been used to describe an
amusing trick-the-eye drawing resembling a three-pronged fork that
appears to depict a three-dimensional object until one realizes
that the parts fit together in an impossible way.

:BLOB: [acronym, Binary Large OBject] n. Used by database people to
refer to any random large block of bits which needs to be stored in
a database, such as a picture or sound file. The essential point
about a BLOB is that it's an object you can't interpret within the
database itself.

:block: [from process scheduling terminology in OS theory] 1. vi.
To delay or sit idle while waiting for something. "We're blocking
until everyone gets here." Compare {busy-wait}. 2. `block
on' vt. To block, waiting for (something). "Lunch is blocked on
Phil's arrival."

:block transfer computations: n. From the television series
"Dr. Who", in which it referred to computations so fiendishly
subtle and complex that they could not be performed by machines.