See more synonyms for bug on Thesaurus.com
  1. Also called true bug, hemipteran, hemipteron. a hemipterous insect.
  2. (loosely) any insect or insectlike invertebrate.
  3. Informal. any microorganism, especially a virus: He was laid up for a week by an intestinal bug.
  4. Informal. a defect or imperfection, as in a mechanical device, computer program, or plan; glitch: The test flight discovered the bugs in the new plane.
  5. Informal.
    1. a person who has a great enthusiasm for something; fan or hobbyist: a hi-fi bug.
    2. a craze or obsession: He's got the sports-car bug.
  6. Informal.
    1. a hidden microphone or other electronic eavesdropping device.
    2. any of various small mechanical or electrical gadgets, as one to influence a gambling device, give warning of an intruder, or indicate location.
  7. a mark, as an asterisk, that indicates a particular item, level, etc.
  8. Horse Racing. the five-pound weight allowance that can be claimed by an apprentice jockey.
  9. a telegraph key that automatically transmits a series of dots when moved to one side and one dash when moved to the other.
  10. Poker Slang. a joker that can be used only as an ace or as a wild card to fill a straight or a flush.
  11. Printing. a label printed on certain matter to indicate that it was produced by a union shop.
  12. any of various fishing plugs resembling an insect.
  13. Chiefly British. a bedbug.
verb (used with object), bugged, bug·ging. Informal.
  1. to install a secret listening device in (a room, building, etc.) or on (a telephone or other device): The phone had been bugged.
  2. to bother; annoy; pester: She's bugging him to get her into show business.
Verb Phrases
  1. bug off, Slang. to leave or depart, especially rapidly: I can't help you, so bug off.
  2. bug out, Slang. to flee in panic; show panic or alarm.
  1. put a bug in someone's ear, to give someone a subtle suggestion; hint: We put a bug in his ear about a new gymnasium.

Origin of bug

1615–25; 1885–90 for def 4; 1910–15 for def 5a; 1915–20 for def 14; 1945–50 for def 15; earlier bugge beetle, apparently alteration of Middle English budde, Old English -budda beetle; sense “leave” obscurely related to other senses and perhaps of distinct orig.
Related formsun·bugged, adjective

Synonyms for bug

See more synonyms for on Thesaurus.com
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for bug off

depart, leave, scram, split

British Dictionary definitions for bug off


  1. any insect of the order Hemiptera, esp any of the suborder Heteroptera, having piercing and sucking mouthparts specialized as a beak (rostrum)See also assassin bug, bedbug, chinch bug
  2. mainly US and Canadian any insect, such as the June bug or the Croton bug
  3. informal
    1. a microorganism, esp a bacterium, that produces disease
    2. a disease, esp a stomach infection, caused by a microorganism
  4. informal an obsessive idea, hobby, etc; craze (esp in the phrases get the bug, be bitten by the bug, the bug bites, etc)
  5. informal a person having such a craze; enthusiast
  6. (often plural) informal an error or fault, as in a machine or system, esp in a computer or computer program
  7. informal a concealed microphone used for recording conversations, as in spying
  8. US (in poker) a joker used as an ace or wild card to complete a straight or flush
verb bugs, bugging or bugged informal
  1. (tr) to irritate; bother
  2. (tr) to conceal a microphone in (a room, etc)
  3. (intr) US (of eyes) to protrude
See also bug out

Word Origin for bug

C16: of uncertain origin; perhaps related to Old English budda beetle


  1. obsolete an evil spirit or spectre; hobgoblin

Word Origin for bug

C14 bugge, perhaps from Middle Welsh bwg ghost. See also bugbear, bugaboo


  1. a past tense and past participle of big 2


  1. Also called: Southern Bug a river in E Europe, rising in W Ukraine and flowing southeast to the Dnieper estuary and the Black Sea. Length: 853 km (530 miles)
  2. Also called: Western Bug a river in E Europe, rising in SW Ukraine and flowing northwest to the River Vistula in Poland, forming part of the border between Poland and Ukraine. Length: 724 km (450 miles)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for bug off

by 1956, perhaps from bugger off (see bugger (v.)), which chiefly is British (by 1920s) but was picked up in U.S. Air Force slang in the Korean War.



"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.



"to scram, skedaddle," 1953, of uncertain origin, perhaps related to bug (v.2), and cf. bug off.

Online Etymology Dictionary, © 2010 Douglas Harper

bug off in Medicine


  1. A true bug, specifically one having a beaklike structure that allows piercing and sucking.
  2. An insect or similar organism, such as a centipede or an earwig.
  3. A disease-producing microorganism, such as a flu bug.
  4. The illness or disease so produced.
  5. A defect or difficulty, as in a system or design.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

bug off in Science


  1. An insect belonging to the suborder Heteroptera. See more at true bug.
  2. An insect, spider, or similar organism. Not in scientific use.
Usage: 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.”
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

bug off in Culture


A generic term that describes a malfunction of undetermined origin in a computer or other electronic device.


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.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Idioms and Phrases with bug off

bug off

Also, bugger off. Go away, as in Bug off before I call the police. Both terms are often used as an imperative, as in the example, and the variant is heard more in Britain than in America. [Slang; c. 1900] For a synonym, see buzz off.


In addition to the idioms beginning with bug

  • bug off
  • bug out

also see:

  • cute as a button (bug's ear)
  • put a bug in someone's ear
  • snug as a bug in a rug
  • what's eating (bugging) you
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.