What is the X in X-mas?
"insect," 1620s (earliest reference is to bedbugs), of unknown origin, probably but not certainly from or influenced by Middle English bugge "something frightening, scarecrow" (late 14c.), a meaning obsolete since the "insect" sense arose except in bugbear (1570s) and bugaboo (q.v.).
Probably connected with Scottish bogill "goblin, bugbear," or obsolete Welsh bwg "ghost, goblin" (cf. Welsh bwgwl "threat," earlier "fear," Middle Irish bocanách "supernatural being"). Some speculate that these words are from a root meaning "goat" (see buck (n.1)) and represent originally a goat-like spectre. Cf. also bogey (n.1) and German bögge, böggel-mann "goblin." Perhaps influenced in meaning by Old English -budda used in compounds for "beetle" (cf. Low German budde "louse, grub," Middle Low German buddech "thick, swollen").
In the United States bug is not confined, as in England, to the domestic pest, but is applied to all insects of the Coleoptera order, which includes what in this country are generally called beetles. [Farmer & Henley, "Dictionary of Slang and Colloquial English," 1912 abridged edition]Meaning "defect in a machine" (1889) may have been coined c.1878 by Thomas Edison (perhaps with the notion of an insect getting into the works). Meaning "person obsessed by an idea" (e.g. firebug) is from 1841, perhaps from notion of persistence. Sense of "microbe, germ" is from 1919. Bugs "crazy" is from c.1900. Bug juice as a slang name for drink is from 1869, originally "bad whiskey." The 1811 slang dictionary has bug-hunter "an upholsterer." Bug-word "word or words meant to irritate and vex" is from 1560s.
"to bulge, protrude," 1872, originally of eyes, perhaps from a humorous or dialect mispronunciation of bulge (v.). Related: Bugged; bugging. As an adjective, bug-eyed recorded from 1872; so commonly used of space creatures in mid-20c. science fiction that the initialism BEM for bug-eyed monster was current by 1953.
"to annoy, irritate," 1949, probably from bug (n.) and a reference to insect pests. Sense of "equip with a concealed microphone" is from 1919. Related: Bugged; bugging.
A true bug, specifically one having a beaklike structure that allows piercing and sucking.
An insect or similar organism, such as a centipede or an earwig.
A disease-producing microorganism, such as a flu bug.
The illness or disease so produced.
A defect or difficulty, as in a system or design.
Our Living Language : The word bug is often used to refer to tiny creatures that crawl along, such as insects and even small animals that are not insects, such as spiders and millipedes. But for scientists the word has a much narrower meaning. In the strictest terms bugs are those insects that have mouthparts adapted for piercing and sucking. The mouthparts of these bugs are contained in a beak-shaped structure. Thus scientists would classify a louse but not a beetle or a cockroach as a bug. In fact, scientists often call lice and their relatives true bugs to distinguish them better from what everyone else calls "bugs."
A generic term that describes a malfunction of undetermined origin in a computer or other electronic device.
Note: The term originated in the 1940s when the examination of a large computer revealed that an actual insect had landed on one of the circuits, shorting it out and shutting the machine down.
To protrude; bulge: Her eyes bugged out when she saw the bill
[1870s+ Dialect; fr humorous or dialectal pronunciation of bulge]
[Imitation of baby talk]
An unwanted and unintended property of a program or piece of hardware, especially one that causes it to malfunction. Antonym of feature. E.g. "There's a bug in the editor: it writes things out backward." The identification and removal of bugs in a program is called "debugging".
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.
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!
Actually, use of "bug" in the general sense of a disruptive event goes back to Shakespeare! 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."
[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 has not yet been exhibited. Thus, the process of investigating the original-computer-bug bug fixed it in an entirely unexpected way, by making the myth true! - ESR]