Definition of "bug"

bug

/bʌɡ/

noun
plural bugs
1. (entomology) An insect of the order Hemiptera (the “true bugs”).
2. Any of various species of marine or freshwater crustaceans; e.g. a Moreton Bay bug, mudbug.
  Quotations
  Bugs, oysters, prawns and crabs […] are plated up on the decks of four side-by-side trawlers bobbing on the calm waters of Trinity Inlet.
  2021 February, The Road Ahead, Brisbane, page 39, column 2
3. (informal) Any insect, arachnid, or other terrestrial arthropod that is a pest.
4. (informal) Any minibeast.
5. (US) Any insect, arachnid, myriapod or entognath.
6. (UK, obsolete, specifically) A bedbug.
  Quotations
  Speaking of advertising changes of name, a title by which those lodging-house pests, bugs, are now often known, that of Norfolk Howards, is derived from an advertisement in which one Ephraim Bug avowed his intention of being for the future known as Norfolk Howard.
  1874, Henry Sampson, A history of advertising, page 278
7. (chiefly computing and engineering jargon) A problem that needs fixing.
  Quotations
  I have the right principle and am on the right track, but time, hard work and some good luck are necessary too. It has been just so in all of my inventions. The first step is an intuition, and comes with a burst, then difficulties arise — this thing gives out and [it is] then that "Bugs" — as such little faults and difficulties are called — show themselves and months of intense watching, study and labor are requisite before commercial success or failure is certainly reached.
  1878, Thomas P. Hughes, quoting Thomas Edison, Edison to Puskas, 13 November 1878, Edison papers, quoted in American Genesis: A History of the American Genius for Invention, Edison National Laboratory, U.S. National Park Service, West Orange, N.J.: Penguin Books, published 1989, page 75
  A... leading aluminum producer claims it has worked all the bugs out of building and servicing aluminum radiators, says it hopes to have a large chunk of the radiator market by the early nineteen seventies.
  1968 April, Popular Mechanics
8. A contagious illness, or a pathogen causing it.
9. (informal) An enthusiasm for something; an obsession.
  Quotations
  As we rode in the bus in the weird phosphorescent void of the Lincoln Tunnel we leaned on each other with fingers waving and yelled and talked excitedly, and I was beginning to get the bug like Dean.
  1957, Jack Kerouac, chapter 1, in On the Road, Viking Press, part 1
10. (informal) A keen enthusiast or hobbyist.
  Quotations
  His mother had been a bug on astrology, which was why the moment of his birth had been impressed on him so exactly.
  1961, Fredric Brown, Nightmare in Yellow
  Incidentally, the camera manufacturers have had a new worry—that they might "kill off the hobby," as U.S. Camera magazine put it recently—by automating to the point that real camera bugs would feel no challenge.
  1961, Kiplinger's Personal Finance, volume 15, number 12, page 34
11. A concealed electronic eavesdropping or intercept device.
12. A small and usually invisible file (traditionally a single-pixel image) on a World Wide Web page, primarily used to track users.
13. (broadcasting) A small, usually transparent or translucent image placed in a corner of a television program to identify the broadcasting network or cable channel.
14. (aviation) A manually positioned marker in flight instruments.
  Quotations
  You look up the proper speed for the phase of flight, set the reminder bug, and then literally forget the speed. You don't read the airspeed number, you fly to the bug.
  2004, Flying Magazine, volume 131, number 10, page 10
15. A semi-automated telegraph key.
  Quotations
  At this point your telegraph operator, sitting at your right, goes "Ticky-tick-tickety-de-tick-tick," with his bug, as he calls his transmitter, and looks at you expectantly.
  1938, Paul Gallico, Farewell to Sport, page 257
  As far as the dashes are concerned, the bug is the same in operation as any regular key would be if it were turned up on edge instead of sitting flat on the desk.
  1942, Arthur Reinhold Nilson, Radio Code Manual, page 134
  I was a very good radio operator. I bought my own bug. That's what the telegraph key in its modern form was called. It was semiautomatic.
  1986, E. L. Doctorow, World's Fair, page 282
16. (obsolete) Hobgoblin, scarecrow; anything that terrifies.
  Quotations
  Sir, spare your threats: / The bug which you would fright me with I seek.
  c. 1610–1611 (date written), William Shakespeare, “The Winters Tale”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene ii]
17. (chiefly LGBT, "the bug") HIV.
  Quotations
  The arguably most debated bareback practice that came to attract attention early on (and still does) was that of "bug chasing," in which HIV-negative men (bug chasers) actively seek out sex with HIV-positive men (gift givers).
  2019, Tora Holmberg, Annika Jonsson, Fredrik Palm, Death Matters: Cultural Sociology of Mortal Life, Springer, page 130
18. (poker) A limited form of wild card in some variants of poker.
19. (paleontology, slang) A trilobite.
  Quotations
  We asked Harris if he had any recommendations about seeing the famous trilobite digs. He said we should just drive out to his claim in the Wheeler Quadrangle, and it was just fine with him if we dug a few bugs.
  2007, Kirk Johnson, Cruisin' the Fossil Freeway, page 174
20. (petroleum industry, slang, dated) Synonym of oil bug.
  Quotations
  Now, only three years later, most of the major oil companies maintain staffs of these men who examine cores, classify the various types of "bugs," or foraminifera, and make charts showing the depths at which each of the hundreds of types is found.
  July 1933, Popular Science
21. (slang, US, horse-racing) An asterisk denoting an apprentice jockey's weight allowance.
  Quotations
  The "bugs" are the asterisks next to the apprentice's name. One bug is a five-pound allowance, two bugs equal seven pounds, and three bugs equal ten pounds.
  1999, Anita Scialli, Inside Track 1999, page 62
22. (slang, US, horse-racing, by extension) A young apprentice jockey.
23. (printing) Synonym of union bug.
24. (gambling, slang) A small piece of metal used in a slot machine to block certain winning combinations.
  Quotations
  Because many illegal slot-machine operators here and abroad do not like to give the slot-machine player even one chance to hit the jackpot or the big bonus, they make use of a "bug." This is a small, flat half-circle of iron about an inch long, which looks something like a bug.
  1961, John Scarne, Complete Guide to Gambling, page 394
25. (gambling, slang) A metal clip attached to the underside of a table, etc. to hold hidden cards, as a form of cheating.
  Quotations
  Some clumsy or audacious sharpers will go so far as to hold out cards in their lap, or stick them in a "bug" under the table.
  1897, Robert Frederick Foster, Foster's Complete Hoyle, page 195
  Fargo had been in a saloon in Kansas when a man was caught using a bug. Made of steel and shaped like a money clip with two sharp ends, the bug was jammed under a table and held cards the bug's owner palmed until they were needed.
  2006, Jon Sharpe, The Trailsman #299: Dakota Danger
verb
third-person singular simple present bugs, present participle bugging, simple past and past participle bugged
1. (informal, transitive) To annoy.
2. (informal, intransitive) To act suspiciously or irrationally, especially in a way that annoys others.
3. (transitive) To install an electronic listening device or devices in.
4. (intransitive, of eyes) To bulge or protrude.
  Quotations
  I well remember the combination of excitement and apprehension with which I tentatively entered my first "rap." My eyes bugged open. There must have been 25 women in the room. I don't think I had ever seen so many lesbians all together in one place before.
  1979 April 28, Lois H. Johnson, “Ten Years of Boston DOB: A Personal Memoir”, in Gay Community News, page 8