The name is from Proto-Germanic *Langgobardoz, often said to mean literally "Long-beards" (see long (adj.) + beard (n.)), but according to OED the second element is perhaps rather from the proper name of the people (Latin Bardi). Their name in Old English was Langbeardas (plural), but also Heaðobeardan, from heaðo "war."
In Middle English the word meant "banker, money-changer, pawnbroker" (late 14c.), especially a Lombard or other Italian trading locally, before it was used in reference to the nationality. The name in Old French (Lombart, Lombert) also meant, in addition, "money-changer; usurer; coward." Lombards were noted throughout medieval Western Europe as bankers and money-lenders, also pawn-brokers. French also gave the word in this sense to Middle Dutch and Low German.
London's Lombard Street (c. 1200) originally was the site of the houses of Lombard (and other Italian) bankers, who dominated the London money-market into Elizabethan times. An old expression for "long odds, much against little" was Lombard Street to a China orange (1815, earlier to an egg-shell, 1763).
region and former kingdom (overthrown 744 by Charlemagne) in northern Italy; see Lombard. Lombardy poplar for the tall, columnar or spire-shaped variety, originally from Italy but planted in North American colonies as an ornamental tree, is attested from 1766.
"timber sawn into rough planks for use," 1660s, American English (Massachusetts), earlier "disused bit of furniture; heavy, useless objects" (1550s), of uncertain origin. It is said to be probably from lumber (v.1) on the notion of "awkward to move," and perhaps to have been influenced by or associated with Lombard (q.v.), the Italian immigrant class famous as pawnbrokers (and money-lenders) in old England. Lumbar and Lumbard were old alternative forms of Lombard in English.
The evolution of sense then would be because a lumber-house ("pawn shop; place where thieves stash stolen property") naturally accumulates odds and ends of furniture. The 19th century guess was that it comes directly from lumber-house or lumber-room in the pawn shop sense, but these are not attested before lumber (n.). Lumber camp is from 1841; lumber-mill is from 1830; lumber-yard is from 1777.
Live Lumber, soldiers or passengers on board a ship are so called by the sailors. [Grose, "Dictionary of the Vulgar Tongue," 1785]
c. 1200, from Late Latin Saxonem (nominative Saxo; also source of French Saxon, Spanish Sajon, Italian Sassone), usually found in plural Saxones, probably from a West Germanic tribal name (represented by Old English Seaxe, Old High German Sahsun, German Sachse "Saxon"), traditionally regarded as meaning literally "warrior with knives" (compare Old English seax, Old Frisian, Old Norse sax "knife, short sword, dagger," Old High German Saxnot, name of a war-god), from Proto-Germanic *sahsa- "knife," from PIE root *sek- "to cut." But Watkins considers this doubtful.
The word figures in the well-known story, related by Geoffrey of Monmouth, who got it from Nennius, of the treacherous slaughter by the Anglo-Saxons of their British hosts:
Accordingly they all met at the time and place appointed, and began to treat of peace; and when a fit opportunity offered for executing his villany, Hengist cried out, "Nemet oure Saxas," and the same instant seized Vortigern, and held him by his cloak. The Saxons, upon the signal given, drew their daggers, and falling upon the princes, who little suspected any such design, assassinated them to the number of four hundred and sixty barons and consuls ....
The OED editors helpfully point out that the correct Old English (with an uninflected plural) would be nimað eowre seax. For other Germanic national names that may have derived from characteristic tribal weapons, see Frank, Lombard. As an adjective from 1560s. Still in 20c. used by Celtic speakers to mean "an Englishman" (Welsh Sais, plural Seison "an Englishman;" Seisoneg "English").
In reference to the modern German state of Saxony (German Sachsen, French Saxe) it is attested from 1630s. Saxon is the source of the -sex in Essex, Sussex, etc. (compare Middlesex, from Old English Middel-Seaxe "Middle Saxons"). Bede distinguished the Anglo-Saxons, who conquered much of southern Britain, from the Ealdesaxe "Old Saxons," who stayed in Germany.
1893, American English, in the figurative sense "fear or doubt that reverses an intention to do something;" the presumed Italian original (avegh minga frecc i pee) is a Lombard proverb meaning "to have no money," but some of the earliest English usages refer to gamblers, so a connection is possible.
1530s, "corner, angle," from French canton "angle, corner (of a room); piece, portion of a country" (13c.), from Italian (Lombard dialect) cantone "region," especially in the mountains, augmentative of Latin canto "section of a country," literally "corner" (see cant (n.2)).
From 1570s as a term in heraldry and flag descriptions. From c. 1600 as "a subdivision of a country;" applied to the sovereign states of the Swiss republic from 1610s.