slug-a-bed 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.

prefix or inseparable particle, a conglomerate of various Germanic and Latin elements.

In words derived from Old English, it commonly represents Old English an "on, in, into" (see on (prep.)), as in alive, above, asleep, aback, abroad, afoot, ashore, ahead, abed, aside, obsolete arank "in rank and file," etc., forming adjectives and adverbs from nouns, with the notion "in, at; engaged in." In this use it is identical to a (2).

It also can represent Middle English of (prep.) "off, from," as in anew, afresh, akin, abreast. Or it can be a reduced form of the Old English past participle prefix ge-, as in aware.

Or it can be the Old English intensive a-, originally ar- (cognate with German er- and probably implying originally "motion away from"), as in abide, arise, awake, ashamed, marking a verb as momentary, a single event. Such words sometimes were refashioned in early modern English as though the prefix were Latin (accursed, allay, affright are examples).

In words from Romanic languages, often it represents reduced forms of Latin ad "to, toward; for" (see ad-), or ab "from, away, off" (see ab-); both of which by about 7c. had been reduced to a in the ancestor of Old French. In a few cases it represents Latin ex.

[I]t naturally happened that all these a- prefixes were at length confusedly lumped together in idea, and the resultant a- looked upon as vaguely intensive, rhetorical, euphonic, or even archaic, and wholly otiose. [OED]