bedbug n.

Old English bedd "bed, couch, resting place; garden plot," from Proto-Germanic *badja- (source also of Old Frisian, Old Saxon bed, Middle Dutch bedde, Old Norse beðr, Old High German betti, German Bett, Gothic badi "bed"). This is said to mean perhaps "sleeping place dug in the ground," if it is from PIE root *bhedh- "to dig, pierce" (source also of Hittite beda- "to pierce, prick," Greek bothyros "pit," Latin fossa "ditch," Lithuanian bedu, besti "to dig," Breton bez "grave"). But Boutkan doubts this and finds little reason to assume that Germanic peoples "(still) lived under such primitive circumstances that they dug out their places to sleep."

Both the sleeping and gardening senses are found in Old English; the specific application to planting also is found also in Middle High German and is the only sense of Danish bed. The meaning "bottom of a lake, sea, or watercourse" is from 1580s. The geological sense of "a thick layer, stratum" is from 1680s.

Bed and board "in bed and at the table" (early 13c.) was a term in old law applied to conjugal duties of man and wife; it also could mean "meals and lodging, room and board" (mid-15c.). Bed-and-breakfast in reference to overnight accommodations is from 1838; as a noun, in reference to a place offering such, by 1967.

"insect, beetle," 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 word or meaning that has become obsolete since the "insect" sense arose, except in bugbear (1570s) and bugaboo (q.v.).

The Middle English word probably is connected with Scottish bogill "goblin, bugbear," or obsolete Welsh bwg "ghost, goblin" (compare 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 specter. Compare also bogey (n.1) and Puck. Middle English Compendium compares Low German bögge, böggel-mann "goblin." The sense shift perhaps was by influence of Old English -budda, used in compounds for "beetle" (compare Low German budde "louse, grub," Middle Low German buddech "thick, swollen").

The name of bug is given in a secondary sense to insects considered as an object of disgust and horror, and in modern English is appropriated to the noisome inhabitants of our beds, but in America is used as the general appellation of the beetle tribe .... A similar application of the word signifying an object dread to creeping things is very common. [Hensleigh Wedgwood, "A Dictionary of English Etymology," 1859]

The 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). In compounds, the meaning "person obsessed by an idea" (as in firebug "arsonist") is from 1841, perhaps from notion of persistence. The colloquial 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.