"bottom of a bag," c. 1400, from bag (n.) + end (n.).
Entries linking to bag-end
bag n.
"small sack," c. 1200, bagge, probably from Old Norse baggi "pack, bundle," or a similar Scandinavian source. OED rejects connection to other Germanic words for "bellows, belly" as without evidence and finds a Celtic origin untenable. In some senses perhaps from Old French bague, which is also from Germanic.
As disparaging slang for "woman" it dates from 1924 in modern use (but various specialized senses of this are much older, and compare baggage). The meaning "person's area of interest or expertise" is by 1964, from African-American vernacular, from jazz sense of "category," probably via notion of putting something in a bag. The meaning "fold of loose skin under the eye" is by 1867. Related: bags.
To be left holding the bag (and presumably nothing else), "cheated, swindled" is attested by 1793. Many figurative senses, such as the verb meaning "to kill game" (1814) and its colloquial extension to "catch, seize, steal" (1818) are from the notion of the game bag (late 15c.) into which the product of the hunt was placed. This also probably explains modern slang in the bag "assured, certain" (1922, American English).
To let the cat out of the bag "reveal the secret" is from 1760. The source is probably the French expression Acheter chat en poche "buy a cat in a bag," which is attested in 18c. French and explained in Bailey's "Universal Etymological English Dictionary" (1736), under the entry for To buy a pig in a poke as "to buy a Thing without looking at it, or enquiring into the Value of it." (Similar expressions are found in Italian and German; and in English, Wycliffe (late 14c.) has To bye a catte in þo sakke is bot litel charge). Thus to let the cat out of the bag would be to inadvertently reveal the hidden truth of a matter one is attempting to pass off as something better or different, which is in line with the earliest uses in English.
Sir Joseph letteth the cat out of the bag, and sheweth principles inimical to the cause of true philosophy, by wishing to make great men Fellows, instead of wise men ["Peter Pindar," "Peter's Prophecy," 1788]
end n.
Old English ende "end, conclusion, boundary, district, species, class," from Proto-Germanic *andiaz (source also of Old Frisian enda, Old Dutch ende, Dutch einde, Old Norse endir "end;" Old High German enti "top, forehead, end," German Ende, Gothic andeis "end"), originally "the opposite side," from PIE *antjo "end, boundary," from root *ant- "front, forehead," with derivatives meaning "in front of, before."
Worldly wealth he cared not for, desiring onely to make both ends meet. [Thomas Fuller, "The History of the Worthies of England," 1662]
Original sense of "outermost part" is obsolete except in phrase ends of the earth. Sense of "destruction, death" was in Old English. Meaning "division or quarter of a town" was in Old English. The end "the last straw, the limit" (in a disparaging sense) is from 1929. The end-man in minstrel troupes was one of the two at the ends of the semicircle of performers, who told funny stories and cracked jokes with the middle-man. U.S. football end zone is from 1909 (end for "side of the field occupied by one team" is from 1851). The noun phrase end-run is attested from 1893 in U.S. football; extended to military tactics by 1940. End time in reference to the end of the world is from 1917. To end it all "commit suicide" is attested by 1911. Be-all and end-all is from Shakespeare ("Macbeth" I.vii.5).