Online Etymology Dictionary

logger (n.2): "one who enters data in a log," 1958, agent noun from log (v.2).
loggerhead (n.): 1580s, "stupid person, blockhead," perhaps from dialectal logger "heavy block of wood" + head (n.). Later it meant "a thick-headed iron tool" (1680s), a type of cannon shot, a type of turtle (1650s). Loggerheads "fighting, fisticuffs" is from 1670s, but the exact notion is uncertain, perhaps it suggests the heavy tools used as weapons. The phrase at loggerheads "in disagreement" is first recorded 1670s.
[W]e three loggerheads be: a sentence frequently written under two heads, and the reader by repeating it makes himself the third. [Grose, "Dictionary of the Vulgar Tongue," 1785]
loggia (n.): "roofed galley used as an open-air room," 1742, from Italian loggia, from French loge (see lodge (n.)).
logging (n.1): "act of felling timber," 1706, verbal noun from log (v.1).
logging (n.2): "act of recording in a log," 1941, verbal noun from log (v.2).
loggy (adj.): "heavy, sluggish," 1847, from log (n.1) + -y (2). Related: Logginess.
logic (n.): mid-14c., "branch of philosophy that treats of forms of thinking," from Old French logique (13c.), from Latin (ars) logica, from Greek logike (techne) "reasoning (art)," from fem. of logikos "pertaining to speaking or reasoning," from logos "reason, idea, word" (see logos). Meaning "logical argumentation" is from c. 1600.
logical (adj.): early 15c., "based on reason," from logic + -al (1). Meaning "pertaining to logic" is c. 1500. Attested from 1860 as "following as a reasonable consequence." Related: Logically.
logician (n.): "person skilled in logic," late 14c., from Old French logicien (13c.), from logique (see logic).
login: in the computer sense, as one word, by 1983, from log in.
logistic (adj.): "pertaining to logic," 1620s, from Medieval Latin logisticus, from Greek logistikos "endued with reason," from logikos (see logic). Related: Logistical (1560s); logistically. Logistics from this word, in the sense "art of arithmetical calculation" is from 1650s.
logistics (n.): "art of moving, quartering, and supplying troops," 1879, from French (l'art) logistique "(art) of quartering troops," from Middle French logis "lodging," from Old French logeiz "shelter for an army, encampment," from loge (see lodge (n.)) + Greek-derived suffix -istique (see -istic). The form in French was influenced by logistique. Related: Logistical.
logjam (n.): also log-jam, "congestion of logs on a river," by 1851, American English; see log (n.1) + jam (v.). The figurative sense is by 1890.
logo (n.): 1937, probably a shortening of logogram "sign or character representing a word."
logo-: before vowels log-, word-forming element meaning "speech, word," from Greek logos "word" (see logos).
logocentric (adj.): "centered on reason," 1931, from logo- + -centric.
logogram (n.): "sign or character representing a word," 1840, from Greek logos (see logos) + -gram. Generically, "any symbol representing graphically a product, idea, etc." is from 1966. The earliest use of the word (1820) is in the sense "logograph," but OED explains this as a substitute "for logograph, which in this sense is itself a mistake for logogriph."
logograph (n.): "instrument for giving a graphic representation of speech," 1879, from Greek logos (see logos) + -graph "instrument for recording; something written." Earliest use (1797) is in the sense "logogriph," and it frequently was used in this sense.
logogriph (n.): a type of word puzzle based on synonyms, etc., and often in the form of a verse, 1590s, from French logogriphe, from Greek logos "word" (see logos) + griphos "riddle," literally "fishing basket."
logolatry (n.): "worship of words," 1810, from logo- + -latry.
logomachy (n.): "contention about, or with, words," 1560s, from logo- + -machy.
logon: in computer sense, as one word, by 1975, from log (v.) + on.
logorrhea (n.): 1878, from logos + ending from diarrhea.
logos (n.): 1580s, Logos, "the divine Word, second person of the Christian Trinity," from Greek logos "word, speech, discourse," also "reason," from PIE root *leg- (1) "to collect" (with derivatives meaning "to speak," on notion of "to pick out words;" see lecture (n.)); used by Neo-Platonists in various metaphysical and theological senses and picked up by New Testament writers.

Other English formations from logos include logolatry "worship of words, unreasonable regard for words or verbal truth" (1810 in Coleridge); logomania (1870); logophobia (1923).
logrolling (n.): also log-rolling, in the legislative vote-trading sense, 1823, American English, from the notion of neighbors on the frontier helping one another with the heavy work of clearing land and building cabins (as in phrase you roll my log and I'll roll yours); see log (n.1) + rolling.
LOG-ROLLING. 1. In the lumber regions of Maine it is customary for men of different logging camps to appoint days for helping each other in rolling the logs to the river, after they are felled and trimmed -- this rolling being about the hardest work incident to the business. Thus the men of three or four camps will unite, say on Monday, to roll for camp No. 1, -- on Tuesday for camp No. 2, -- on Wednesday for camp No. 3, -- and so on, through the whole number of camps within convenient distance of each other. [Bartlett]
logy (adj.): "dull and heavy," 1848, American English, perhaps from Dutch log "heavy, dull" + -y (2); compare Middle Low German luggich "sleepy, sluggish." Or perhaps a variant of loggy.
loimic (adj.): "pertaining to plague," 1822, from Greek loimikos, from loimos "plague, pestilence."
loin (n.): early 14c., "side of the body of an animal used for food," from Old French loigne "hip, haunch, lumbar region," from Vulgar Latin *lumbea, from *lumbea caro "meat of the loin," from fem. of *lumbeus, adjective used as a noun, from Latin lumbus "loin" (see lumbago).

Replaced Old English lendenu "loins," from Proto-Germanic *landwin- (source also of German Lende "loin," Lenden "loins;" Old High German lenti, Old Saxon lendin, Middle Dutch lendine, Dutch lende, Old Norse lend).

The Latin word perhaps was borrowed from a Germanic source. In reference to the living human body, it is attested from late 14c. In Biblical translations, often used for "that part of the body that should be covered and about which the clothes are bound" (1520s). Related: Loins.
loincloth (n.): 1859, from loin + cloth.
loiter (v.): early 15c., "idle one's time, dawdle over work," from Middle Dutch loteren "be loose or erratic, shake, totter" like a loose tooth or a sail in a storm; in modern Dutch, leuteren "to delay, linger, loiter over one's work." Probably cognate with Old English lutian "lurk," and related to Old English loddere "beggar;" Old High German lotar "empty, vain," luzen "lurk;" German Lotterbube "vagabond, rascal," lauschen "eavesdrop;" Gothic luton "mislead;" Old English lyðre "base, bad, wicked." Related: Loitered; loitering.
loitering (n.): mid-14c., verbal noun from loiter.
lol: by 1993, computer chat abbreviation of laughing out loud.
Lola: fem. proper name, diminutive of Spanish Dolores.
Lolita: fem. proper name, diminutive of Lola. Title and name of character in the 1958 novel by Vladimir Nabokov (1899-1977) about a precocious schoolgirl seduced by an older man; by 1960 the name was in widespread figurative use.
loll (v.): mid-14c., lollen "to lounge idly, hang loosely," perhaps related to Middle Dutch lollen "to doze, mumble," or somehow imitative of rocking or swinging. Specifically of the tongue from 1610s. Related: Lolled; lolling. As a noun, from 1709. Grose ["Dictionary of the Vulgar Tongue," 1785] has lollpoop "A lazy, idle drone."
lollapalooza (n.): also lallapaloosa, lallapalootza, etc.; "remarkable or wonderful person or thing," 1901, American English, fanciful formation. The annual North American alternative pop music concert of the same name dates from 1991.
Lollard: name for certain heretics, late 14c. (in Chaucer, Loller, c. 1386), from Middle Dutch lollaerd, applied pejoratively to members of reforming sects c. 1300 who devoted themselves to the care of the sick and poor, literally "mumbler, mutterer," so called by critics who regarded them as heretics pretending to humble piety, from lollen "to mumble or doze." Generic late Middle English term for groups suspected of heresy, especially followers of John Wyclif.
lollipop (n.): 1784, lolly-pops "sweetmeats, soft candy," perhaps related to loll "to dangle" (the tongue) + pop "strike, slap." Or the first element may be northern dialectal lolly "the tongue." Meaning "hard candy on a stick" is from 1920s.
lolly (n.): 1854, short for lollipop. In 20c. British slang, also "money."
lollygag (v.): "dawdle, dally," 1862, lallygag, American English, perhaps from dialectal lolly "tongue" + gag "deceive, trick." Related: Lollygagged; lollygagging.
Lombard (n.): from Late Latin Langobardus, proper name of a Germanic people who originated in Scandinavia, migrated to the Elbe area 1 c. C.E., then to Pannonia (5 c.) and in 6 c. conquered northern Italy and settling in the northern region that became known as Lombardy, ruling for two centuries. Their name is from Proto-Germanic Langgobardoz, often said to mean literally "Long-beards," but perhaps rather from *lang- "tall, long" + 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.), from Old French Lombart "Lombard," also "money-changer; usurer; coward," from Italian Lombardo (from Medieval Latin Lombardus). Lombards in Middle Ages were notable throughout Western Europe as bankers and money-lenders, also pawn-brokers; they established themselves in France from 13c., especially in Montpellier and Cahors, and London's Lombard Street (c. 1200) originally was the site of the houses of Lombard bankers. French also gave the word in this sense to Middle Dutch and Low German. Lombardy poplar, originally from Italy but planted in North American colonies as an ornamental tree, is attested from 1766.
Lombardic: 1690s, from Lombard + -ic.
London: chief city and capital of England, Latin Londinium (c.115), often explained as "place belonging to a man named Londinos," a supposed Celtic personal name meaning "the wild one," "but this etymology is rejected in an emphatic footnote in Jackson 1953 (p.308), and we have as yet nothing to put in its place" [Margaret Gelling, "Signposts to the Past: Place-Names and the History of England," Chichester, 1978]. London Bridge the children's singing game is attested from 1827. London broil "large flank steak broiled then cut in thin slices" attested by 1939, American English; London fog first attested 1830.
Londoner (n.): "resident or native of London," mid-15c., from London + -er (1). Earlier (late 14c.) was Anglo-French Londenois.
lone (adj.): late 14c., "having no companion, solitary," shortening of alone (q.v.) by weakening of stress or else by misdivision of what is properly all one. The Lone Star in reference to "Texas" is first recorded 1843, from its flag. Lone wolf in the figurative sense is 1909, American English.
loneliness (n.): 1580s, from lonely + -ness.
lonely (adj.): c. 1600, "solitary, lone," from lone + -ly (1). Meaning "dejected for want of company" is from 1811. Lonely heart (n.) "a lonely-hearted person" is from 1922. Lonely hearted (adj.) is attested from 1820.
loner (n.): "one who avoids company," 1946; see lone. Apparently first in U.S. baseball slang (earliest reference is to Ted Williams).
Ted is likable enough in spite of his obsession with his specialty. He is something of a "loner," and he refuses to pal around with his teammates in off hours, but in the clubhouse he does his share of the talking. ["Life" magazine, Sept. 23, 1946]
lonesome (adj.): 1640s, from lone + -some (1). Related: Lonesomeness.
long (adj.): "that extends considerably from end to end," Old English lang "long," from Proto-Germanic *langgaz (source also of Old Frisian and Old Saxon lang, Old High German and German lang, Old Norse langr, Middle Dutch lanc, Dutch lang, Gothic laggs "long").

The Germanic words are perhaps from PIE *dlonghos- (source also of Latin longus, Old Persian darga-, Persian dirang, Sanskrit dirghah, Greek dolikhos "long," Greek endelekhes "perpetual," Latin indulgere "to indulge"), from root *del- "long."

The adverb is from Old English lange, longe, from the adjective. No longer "not as formerly" is from c. 1300; to be not long for this world "soon to die" is from 1714.

The word illustrates the Old English tendency for short "a" to become short "o" before -n- (also retained in bond/band and West Midlands dialectal lond from land and hond from hand).

Long vowels (c. 1000) originally were pronounced for an extended time. Sporting long ball is from 1744, originally in cricket. Long jump as a sporting event is attested from 1864. A ship's long-boat so called from 1510s. Long knives, name Native Americans gave to white settlers (originally in Virginia/Kentucky) is from 1774. Long in the tooth (1841 of persons) is from horses showing age by recession of gums. Long time no see, imitative of American Indian speech, is first recorded 1900. To be long on something, "have a lot" of it, is from 1900, American English slang.