The DICT Development Group

  bug
   n.
  
      An unwanted and unintended property of a program or piece of hardware, esp.
      one that causes it to malfunction. Antonym of feature. Examples: ?There's
      a bug in the editor: it writes things out backwards.? ?The system crashed
      because of a hardware bug.? ?Fred is a winner, but he has a few bugs?
      (i.e., Fred is a good guy, but he has a few personality problems).
  
      Historical note: Admiral Grace Hopper (an early computing pioneer better
      known for inventing COBOL) liked to tell a story in which a technician
      solved a glitch in the Harvard Mark II machine by pulling an actual
      insect out from between the contacts of one of its relays, and she
      subsequently promulgated bug in its hackish sense as a joke about the
      incident (though, as she was careful to admit, she was not there when it
      happened). For many years the logbook associated with the incident and the
      actual bug in question (a moth) sat in a display case at the Naval Surface
      Warfare Center (NSWC). The entire story, with a picture of the logbook and
      the moth taped into it, is recorded in the Annals of the History of
      Computing, Vol. 3, No. 3 (July 1981), pp. 285--286.
  
      The text of the log entry (from September 9, 1947), reads ?1545 Relay #70
      Panel F (moth) in relay. First actual case of bug being found?. This
      wording establishes that the term was already in use at the time in its
      current specific sense ? and Hopper herself reports that the term bug was
      regularly applied to problems in radar electronics during WWII.
  
      [bugpic-col]
  
      The ?original bug? (the caption date is incorrect)
  
      Indeed, the use of bug to mean an industrial defect was already established
      in Thomas Edison's time, and a more specific and rather modern use can be
      found in an electrical handbook from 1896 (Hawkin's New Catechism of
      Electricity, Theo. Audel & Co.) which says: ?The term ?bug? is used to a
      limited extent to designate any fault or trouble in the connections or
      working of electric apparatus.? It further notes that the term is ?said to
      have originated in quadruplex telegraphy and have been transferred to all
      electric apparatus.?
  
      The latter observation may explain a common folk etymology of the term;
      that it came from telephone company usage, in which ?bugs in a telephone
      cable? were blamed for noisy lines. Though this derivation seems to be
      mistaken, it may well be a distorted memory of a joke first current among
      telegraph operators more than a century ago!
  
      Or perhaps not a joke. Historians of the field inform us that the term ?bug
      ? was regularly used in the early days of telegraphy to refer to a variety
      of semi-automatic telegraphy keyers that would send a string of dots if you
      held them down. In fact, the Vibroplex keyers (which were among the most
      common of this type) even had a graphic of a beetle on them (and still do)!
      While the ability to send repeated dots automatically was very useful for
      professional morse code operators, these were also significantly trickier
      to use than the older manual keyers, and it could take some practice to
      ensure one didn't introduce extraneous dots into the code by holding the
      key down a fraction too long. In the hands of an inexperienced operator, a
      Vibroplex ?bug? on the line could mean that a lot of garbled Morse would
      soon be coming your way.
  
      Further, the term ?bug? has long been used among radio technicians to
      describe a device that converts electromagnetic field variations into
      acoustic signals. It is used to trace radio interference and look for
      dangerous radio emissions. Radio community usage derives from the
      roach-like shape of the first versions used by 19th century physicists. The
      first versions consisted of a coil of wire (roach body), with the two wire
      ends sticking out and bent back to nearly touch forming a spark gap (roach
      antennae). The bug is to the radio technician what the stethoscope is to
      the stereotypical medical doctor. This sense is almost certainly ancestral
      to modern use of ?bug? for a covert monitoring device, but may also have
      contributed to the use of ?bug? for the effects of radio interference
      itself.
  
      Actually, use of bug in the general sense of a disruptive event goes back
      to Shakespeare! (Henry VI, part III - Act V, Scene II: King Edward: ?So,
      lie thou there. Die thou; and die our fear; For Warwick was a bug that
      fear'd us all.?) In the first edition of Samuel Johnson's dictionary one
      meaning of bug is ?A frightful object; a walking spectre?; this is traced
      to ?bugbear?, a Welsh term for a variety of mythological monster which (to
      complete the circle) has recently been reintroduced into the popular
      lexicon through fantasy role-playing games.
  
      In any case, in jargon the word almost never refers to insects. Here is a
      plausible conversation that never actually happened: ?There is a bug in
      this ant farm!? ?What do you mean? I don't see any ants in it.? ?That's the
      bug.?
  
      A careful discussion of the etymological issues can be found in a paper by
      Fred R. Shapiro, 1987, ?Entomology of the Computer Bug: History and
      Folklore?, American Speech 62(4):376-378.
  
      [There has been a widespread myth that the original bug was moved to the
      Smithsonian, and an earlier version of this entry so asserted. A
      correspondent who thought to check discovered that the bug was not there.
      While investigating this in late 1990, your editor discovered that the NSWC
      still had the bug, but had unsuccessfully tried to get the Smithsonian to
      accept it ? and that the present curator of their History of American
      Technology Museum didn't know this and agreed that it would make a
      worthwhile exhibit. It was moved to the Smithsonian in mid-1991, but due to
      space and money constraints was not actually exhibited for years
      afterwards. Thus, the process of investigating the original-computer-bug
      bug fixed it in an entirely unexpected way, by making the myth true! ?ESR]
  
      [73-07-29]
  
      It helps to remember that this dates from 1973.