v. t. to annoy; to bother or pester. [ PJC ]

n. [ OE. bugge, fr. W. bwg, bwgan, hobgoblin, scarecrow, bugbear. Cf. Bogey, Boggle. ] 1. A bugbear; anything which terrifies. [ Obs. ] [ 1913 Webster ]

Sir, spare your threats:
The bug which you would fright me with I seek. Shak. [ 1913 Webster ]

2. (Zool.) A general name applied to various insects belonging to the Hemiptera; as, the squash bug; the chinch bug, etc. [ 1913 Webster ]

3. (Zool.) An insect of the genus Cimex, especially the bedbug (Cimex lectularius). See Bedbug. [ 1913 Webster ]

4. (Zool.) One of various species of Coleoptera; as, the ladybug; potato bug, etc.; loosely, any beetle. [ 1913 Webster ]

5. (Zool.) One of certain kinds of Crustacea; as, the sow bug; pill bug; bait bug; salve bug, etc. [ 1913 Webster ]

☞ According to popular usage in England and among housekeepers in America around 1900, bug, when not joined with some qualifying word, was used specifically for bedbug. As a general term it is now used very loosely in America as a colloquial term to mean any small crawling thing, such as an insect or arachnid, and was formerly used still more loosely in England. “God's rare workmanship in the ant, the poorest bug that creeps.” Rogers (Naaman). “This bug with gilded wings.” Pope. [ 1913 Webster +PJC ]

6. (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. “That's not a bug, it's a feature!” [ PJC ]

7. Any unexpected defect or flaw, such as in a machine or a plan. [ PJC ]

8. A hidden electronic listening device, used to hear or record conversations surreptitiously. [ PJC ]

9. An infectious microorganism; a germ{ 4 }. [ Colloq. ] [ PJC ]

10. An undiagnosed illness, usually mild, believed to be caused by an infectious organism. [ Colloq. ] In some communities in the 1990's, the incidence of AIDS is high and AIDS is referred to colloquially as “the bug”. [ PJC ]

11. An enthusiast; -- used mostly in combination, as a camera bug. [ Colloq. ] [ PJC ]

Bait bug. See under Bait. --
Bug word, swaggering or threatening language. [ Obs. ] Beau. & Fl. [ 1913 Webster ]

n. (Bot.) A perennial white-flowered herb of the order Ranunculaceæ and genus Cimiciguga; bugwort. There are several species. [ 1913 Webster ]

v. t. To alarm with idle phantoms. [ 1913 Webster ]

{ } n. [ See Bug. ] Something frightful, as a specter; anything imaginary that causes needless fright; something used to excite needless fear; also, something really dangerous, or an imaginary monster, used to frighten children, etc. “Bugaboos to fright ye.” Lloyd. [ 1913 Webster ]

But, to the world no bugbear is so great
As want of figure and a small estate. Pope. [ 1913 Webster ]

The bugaboo of the liberals is the church pray. S. B. Griffin. [ 1913 Webster ]

The great bugaboo of the birds is the owl. J. Burroughs. [ 1913 Webster ]

2. a source of concern; as, the old bugaboo of inflation still bothers them. [ WordNet 1.5 ]

Syn. -- Hobgoblin; goblin; specter; ogre; scarecrow; bogeyman; boogeyman; booger. [ 1913 Webster ]

n. Same as Bugaboo. -- a. Causing needless fright. Locke. [ 1913 Webster ]

n. (Zool.) The menhaden. [ U.S. ] [ 1913 Webster ]

n. [ F. bougre, fr. LL. Bulgarus, a Bulgarian, and also a heretic; because the inhabitants of Bulgaria were infected with heresy. Those guilty of the crime of buggery were called heretics, because in the eyes of their adversaries there was nothing more heinous than heresy, and it was therefore thought that the origin of such a vice could only be owing to heretics. ] 1. One guilty of buggery or unnatural vice; a sodomite. [ 1913 Webster ]

2. A wretch; -- sometimes used humorously or in playful disparagement. [ Low ] [ 1913 Webster ]

n. [ OF. bougrerie, bogrerie, heresy. See Bugger. ] Unnatural sexual intercourse; sodomy. [ 1913 Webster ]

n. [ From Buggy, a. ] The state of being infested with bugs. [ 1913 Webster ]