bug

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A true bug.
2. n. An insect or similar organism, such as a centipede or an earwig. See Regional Note at lightning bug.
3. n. A disease-producing microorganism: a flu bug.
4. n. The illness or disease so produced: "stomach flu, a cold, or just some bug going around” ( David Smollar).
5. n. A defect or difficulty, as in a system or design.
6. n. Computer Science A defect in the code or routine of a program.
7. n. An enthusiasm or obsession: got bitten by the writing bug.
8. n. An enthusiast or devotee; a buff: a model train bug.
9. n. An electronic listening device, such as a hidden microphone or wiretap, used in surveillance: planted a bug in the suspect's room.
10. v. To grow large; bulge: My eyes bugged when I saw the mess.
11. v. To annoy; pester.
12. v. To prey on; worry: a memory that bugged me for years.
13. v. To equip (a room or telephone circuit, for example) with a concealed electronic listening device.
14. v. To make (the eyes) bulge or grow large.
15. bug off Slang To leave someone alone; go away.
16. bug out Slang To leave or quit, usually in a hurry.
17. bug out Slang To avoid a responsibility or duty. Often used with on or of: bugged out on his partners at the first sign of trouble.
18. idiom. put a bug in (someone's) ear Informal To impart useful information to (another) in a subtle, discreet way.

Century Dictionary and Cyclopedia

1. n. A hobgoblin; a specter; anything terrifying; a bugbear.
2. n. A term loosely applied to many kinds of insects, commonly with certain distinctive additions, as May-bug, lady-bug, land-bugs (Geocorisæ), water-bugs (Hydrocorisæ), etc.
3. n. Especially The Cimex lectularius, the bedbug or house-bug, or any member of this genus or of the family Cimicidæ. The bedbug is about inch long, wingless, with a roundish, depressed body, of dirty rust-color, and emits an offensive smell when touched. The female lays her eggs in summer in the crevices of furniture and of the walls of rooms. Its larvæ are small, white, and semi-transparent. They attain full size in eleven weeks. The mouth of the bedbug has a 3-jointed proboscis, which forms a sheath for a sucker.
4. n. plural In entomology, the Hemiptera, and especially the heteropterous division of that order.
5. n. An entomostracous crustacean of cursorial habit or bug-like aspect, as an isopod. Some are parasites of fishes, others terrestrial. See bugfish, salve-bug, sowbug, pill-bug.
6. To hunt for bugs; collect or destroy insects: chiefly in the present participle: as, to go bugging.
7. To bend.
8. Big; threatening.
9. Proud; self-important; pompous; conceited.

Wiktionary

1. n. An insect of the order Hemiptera (the "true bugs").
2. n. colloquial Any insect, arachnid, or other terrestrial arthropod that is a pest.
3. n. Various species of marine crustaceans; e.g. a Morton Bay bug.
4. n. A problem that needs fixing, especially in computing.
5. n. A contagious illness; a bacterium or virus causing it
6. n. An enthusiasm for something; an obsession
7. n. An electronic intercept device
8. n. A small and and usually invisible file (traditionally a single-pixel image) on a World Wide Web page, primarily used to track users.
9. n. broadcasting A small, usually transparent or translucent image placed in a corner of a television program to indicate what network or cable channel is televising it
10. n. aviation A manually positioned marker in flight instruments
11. n. A semi-automated telegraph key
12. n. (LGBT) The HIV.
13. v. informal, transitive To annoy.
14. v. transitive To install an electronic listening device or devices in.

GNU Webster's 1913

1. n. obsolete A bugbear; anything which terrifies.
2. n. (Zoöl.) A general name applied to various insects belonging to the Hemiptera
3. n. (Zoöl.) An insect of the genus Cimex, especially the bedbug (Cimex lectularius). See Bedbug.
4. n. (Zoöl.) One of various species of Coleoptera.
5. n. (Zoöl.) One of certain kinds of Crustacea
6. n. (Computers) An error in the coding of a computer program, especially one causing the program to malfunction or fail. See, for example, year 2000 bug.
7. n. Any unexpected defect or flaw, such as in a machine or a plan.
8. n. A hidden electronic listening device, used to hear or record conversations surreptitiously.
9. n. colloq. An infectious microorganism; a germ{4}.
10. n. colloq. An undiagnosed illness, usually mild, believed to be caused by an infectious organism.
11. n. colloq. An enthusiast; -- used mostly in combination, .
12. v. to annoy; to bother or pester.

WordNet 3.0

1. v. tap a telephone or telegraph wire to get information
2. n. general term for any insect or similar creeping or crawling invertebrate
3. n. a fault or defect in a computer program, system, or machine
4. v. annoy persistently
5. n. a small hidden microphone; for listening secretly
6. n. insects with sucking mouthparts and forewings thickened and leathery at the base; usually show incomplete metamorphosis
7. n. a minute life form (especially a disease-causing bacterium); the term is not in technical use