Online Etymology Dictionary

Leyden jar (n.): 1755, phial used for accumulating and storing static electricity, from Leyden (modern Leiden), city in Holland; so called because it was first described (in 1746) by physicist Pieter van Musschenbroek of Leyden (1692-1761). The place name is said to be from Germanic *leitha- "canal."
lez: also les; by 1929, colloquial shortening of lesbian.
Lhasa apso: type of dog, 1935, from Tibetan, literally "Lhasa terrier," from Lhasa, capital of Tibet.
liability (n.): 1790, originally a term in law; "condition of being legally liable;" see liable + -ity. General sense is from 1809; meaning "thing for which one is liable" is first attested 1842. Related: Liabilities.
liable (adj.): mid-15c., "bound or obliged by law," probably from Anglo-French *liable, from Old French lier "to bind, tie up, fasten, tether; bind by obligation," from Latin ligare "to bind, to tie" (see ligament). With -able. General sense of "exposed to" (something undesirable) is from 1590s. Incorrect use for "likely" is attested by 1886.
liaise (v.): 1928, back-formation from liaison. Said to be a coinage of British military men in World War I. Related: Liaised; liaising.
liaison (n.): 1640s, from French liaison "a union, a binding together" (13c.), from Late Latin ligationem (nominative ligatio) "a binding," from past participle stem of Latin ligare "to bind" (see ligament). Originally a cookery term for a thickening agent for sauces. Sense of "intimate relations" is from 1806. Military sense of "cooperation between branches, allies, etc." is from 1816. The noun meaning "one who is concerned with liaison of units, etc." is short for liaison officer.
liar (n.): early 13c., from Old English leogere "liar, false witness," agent noun from Anglian legan, West Saxon leogan "be untruthful, lie" (see lie (v.1)). "The form in -ar is probably in imitation of the refashioned forms such as scholar for scoler and pillar for piler." [Barnhart]
lib (n.): 1969, American English, shortening of liberation, used with possessives, originally in Women's Lib. Colloquial shortening libber for liberationist is attested from 1971.
libation (n.): late 14c., "pouring out of wine in honor of a god," from Latin libationem (nominative libatio) "a drink offering," noun of action from past participle stem of libare "pour out (an offering)," from PIE *(s)leib- "to pour, drop" (cf. Greek leibein "to pour, make a libation"), an enlargement of root *lei- "to pour, to flow" (cf. Sanskrit riyati "to let run;" Greek aleison "a wine vessel;" Lithuanian lieju "to pour," lytus "rain;" Hittite lilai- "to let go;" Albanian lyse, lise "a stream;" Welsh lliant "a stream, a sea," llifo "to flow;" Old Irish lie "a flood;" Breton livad "inundation;" Gaelic lighe "a flood, overflow;" Gothic leithu "fruit wine;" Old Church Slavonic liti, lêju, Bulgarian leja "I pour;" Czech liti, leji, Old Polish lić "to pour"). Transferred sense of "liquid poured out to be drunk" is from 1751. Related: Libations.
libel (n.): c.1300, "formal written statement," especially, in civil law, "plaintiff's statement of charges" (mid-14c.); from Old French libelle (fem.) "small book; (legal) charge, claim; writ; written report" (13c.), from Latin libellus "a little book, pamphlet; petition, written accusation, complaint," diminutive of liber "book" (see library). Broader sense of "any published or written statement likely to harm a person's reputation" is first attested 1630s.
libel (v.): mid-15c., "make an initial statement setting out a plaintiff's case" (modern sense from 1560s), from libel (n.), q.v. for sense development. Related: Libeled; libelled; libeling; libelling.
libelous (adj.): also libellous, 1610s, from libel (n.) + -ous. Related: Libelously; libelousness.
liberal (adj.): mid-14c., "generous," also, late 14c., "selfless; noble, nobly born; abundant," and, early 15c., in a bad sense "extravagant, unrestrained," from Old French liberal "befitting free men, noble, generous, willing, zealous" (12c.), from Latin liberalis "noble, gracious, munificent, generous," literally "of freedom, pertaining to or befitting a free man," from liber "free, unrestricted, unimpeded; unbridled, unchecked, licentious," from PIE *leudh-ero- (cf. Greek eleutheros "free"), probably originally "belonging to the people" (though the precise semantic development is obscure), and a suffixed form of the base *leudh- "people" (cf. Old Church Slavonic ljudu, Lithuanian liaudis, Old English leod, German Leute "nation, people;" Old High German liut "person, people") but literally "to mount up, to grow."

With the meaning "free from restraint in speech or action," liberal was used 16c.-17c. as a term of reproach. It revived in a positive sense in the Enlightenment, with a meaning "free from prejudice, tolerant," which emerged 1776-88.

In reference to education, explained by Fowler as "the education designed for a gentleman (Latin liber a free man) & ... opposed on the one hand to technical or professional or any special training, & on the other to education that stops short before manhood is reached" (cf. liberal arts). Purely in reference to political opinion, "tending in favor of freedom and democracy" it dates from c.1801, from French libéral, originally applied in English by its opponents (often in French form and with suggestions of foreign lawlessness) to the party favorable to individual political freedoms. But also (especially in U.S. politics) tending to mean "favorable to government action to effect social change," which seems at times to draw more from the religious sense of "free from prejudice in favor of traditional opinions and established institutions" (and thus open to new ideas and plans of reform), which dates from 1823.
Conservative, n. A statesman who is enamored of existing evils, as distinguished from the Liberal, who wishes to replace them with others. [Ambrose Bierce, "Devil's Dictionary," 1911]
liberal (n.): 1820, "member of the Liberal party of Great Britain," from liberal (adj.). Used early 20c. of less dogmatic Christian churches; in reference to a political ideology not conservative or fascist but short of socialism, from c.1920.
This is the attitude of mind which has come to be known as liberal. It implies vigorous convictions, tolerance for the opinions of others, and a persistent desire for sound progress. It is a method of approach which has played a notable and constructive part in our history, and which merits a thorough trial today in the attack on our absorbingly interesting American task. [Guy Emerson, "The New Frontier," 1920]
liberal arts: late 14c., translating Latin artes liberales; the seven attainments directed to intellectual enlargement, not immediate practical purpose, and thus deemed worthy of a free man (liberal in this sense is opposed to servile or mechanical). They were divided into the trivium -- grammar, logic, rhetoric -- and the quadrivium -- arithmetic, geometry, music, astronomy.
liberalisation (n.): chiefly British English spelling of liberalization; for spelling, see -ize.
liberalism (n.): 1819, from liberal + -ism.
liberality (n.): mid-14c., "generosity," from Old French liberalité "generosity, liberality" (13c.), from Latin liberalitatem (nominative liberalitas) "way of thinking or acting befitting a free man," noun of quality from liberalis (see liberal (adj.)).
liberalization (n.): 1794; see liberal + -ization.
liberalize (v.): 1774, from liberal (adj.) + -ize. Related: Liberalized; liberalizing.
liberally (adv.): late 14c., "generously, munificently," from liberal (adj.) + -ly (2). Meaning "freely" is c.1500.
liberate (v.): 1620s, from Latin liberatus, past participle of liberare "set free," from liber "free" (see liberal). Meaning "to free an occupied territory from the enemy" (often used ironically) is from 1942. Related: Liberated; liberating.
liberation (n.): early 15c., from Middle French libération and directly from Latin liberationem (nominative liberatio) "a setting or becoming free," noun of action from past participle stem of liberare "set free" (see liberate). Liberation theology (1969) translates Spanish teologia de la liberación, coined 1968 by Peruvian priest Gustavo Gutiérrez.
liberator (n.): 1640s, from Latin liberator "one who sets free, a deliverer," agent noun from past participle stem of liberare (see liberate).
Liberia: African nation, begun as a resettlement project of freed American slaves in 1816 by the American Colonization Society, the name chosen by society member and U.S. senator Robert Goodloe Harper (1765-1825) from Latin liber "free" (see liberal).
libertarian (n.): 1789, "one who holds the doctrine of free will" (opposed to necessitarian), from liberty (q.v.) on model of unitarian, etc. Political sense of "person advocating liberty in thought and conduct" is from 1878. As an adjective by 1882. U.S. Libertarian Party founded in Colorado, 1971.
liberticide (n.): 1793, from liberty + -cide.
libertine (n.): late 14c., "a freedman, an emancipated slave," from Latin libertinus "member of a class of freedmen," from libertus "one's freedmen," from liber "free" (see liberal). Sense of "freethinker" is first recorded 1560s, from French libertin (1540s) originally the name given to certain Protestant sects in France and the Low Countries. Meaning "dissolute or licentious person" first recorded 1590s; the darkening of meaning being perhaps due to misunderstanding of Latin libertinus in Acts vi:9. As an adjective by 1570s.
liberty (n.): late 14c., "free choice, freedom to do as one chooses," from Old French liberté "freedom, liberty, free will" (14c.), from Latin libertatem (nominative libertas) "freedom, condition of a free man; absence of restraint; permission," from liber "free" (see liberal)
The spirit of liberty is the spirit which is not too sure it is right. [Learned Hand, 1944]
Nautical sense of "leave of absence" is from 1758. To take liberties "go beyond the bounds of propriety" is from 1620s. Sense of "privileges by grant" (14c.) led to sense of "a person's private land" (mid-15c.), which yielded sense in 18c. England and America of "a district within a county but having its own justice of the peace," and also "a district adjacent to a city and in some degree under its municipal jurisdiction" (e.g. Northern Liberties of Philadelphia). Also cf. Old French libertés "local rights, laws, taxes."
libidinal (adj.): 1922, in psychology jargon, from libido (Latin genitive libidinis) + -al (1).
libidinous (adj.): "lustful," mid-15c., Old French libidineus (13c., Modern French libidineux), from Latin libidinosus "full of desire, lustful," from libido "pleasure, desire, sensual passion, lust" (see libido). Related: Libidinously; libidinousness.
libido (n.): "psychic drive or energy, usually associated with sexual instinct," 1892, carried over untranslated in English edition of Krafft-Ebing's "Psychopathia Sexualis"; and used in 1909 in A.A. Brill's translation of Freud's "Selected Papers on Hysteria" (Freud's use of the term led to its popularity); from Latin libido "desire, lust," from libere "to be pleasing, to please," ultimately cognate with Old English lufu (see love (n.)).
Libra: zodiac constellation, late Old English, from Latin libra, literally "pound, balance," from Mediterranean base *lithra- "a scale."
librarian (n.): "custodian of a library," 1713; see library + -an. Earlier form was library-keeper (1640s), and librarian was used earlier in a sense "scribe" (1660s).
library (n.): place for books, late 14c., from Anglo-French librarie, Old French librairie "collection of books" (14c.), noun use of adj. librarius "concerning books," from Latin librarium "chest for books," from liber (genitive libri) "book, paper, parchment," originally "the inner bark of trees," probably a derivative of PIE root *leub(h)- "to strip, to peel" (see leaf). The equivalent word in most Romance languages now means "bookseller's shop." Old English had bochord, literally "book hord."
libretto (n.): (plural libretti), 1742, from Italian libretto, diminutive of libro "book," from Latin liber (genitive libri), see library. Related: Librettist.
Libya: north African nation, an ancient name, attested in heiroglyphics from 2000 B.C.E., of unknown origin. In Greek use, sometimes meaning all of Africa. Related: Libyan.
licence (n.): mid-14c., "liberty (to do something), leave," from Old French licence "freedom, liberty, power, possibility; permission," (12c.), from Latin licentia "freedom, liberty, license," from licentem (nominative licens). present participle of licere "to be allowed, be lawful," from PIE root *leik- "to offer, bargain" (cf. Lettish likstu "I come to terms"). Meaning "formal (usually written) permission from authority to do something" (marry, hunt, drive, etc.) is first attested early 15c. Meaning "excessive liberty, disregard of propriety" is from mid-15c. No etymological justification for the spelling with -s-; attempts to confine license to verbal use and licence to noun use (cf. advise/advice, devise/device) seem to have failed.
licence (v.): c.1400, "grant formal authorization," from license (n.). Related: Licenced; Licencing.
license: see licence. Related: Licensed; licensing.
licensee (n.): 1837, from license + -ee.
licensure (n.): 1808, from license + -ure.
licentious (adj.): "morally unrestrained," 1530s, from Medieval Latin licentiosus "full of license, unrestrained," from Latin licentia (see license). Related: Licentiously; licentiousness.
lich (n.): also litch, lych, "body, corpse," southern England dialectal survival of Old English lic "body, dead body, corpse," cognate with Old Frisian lik, Dutch lijk, Old High German lih, German leiche "dead body," Old Norse lik, Danish lig, Gothic leik, from Proto-Germanic *likow. Cf. litch-gate "roofed gate to a churchyard under which a bier is placed to await the coming of the clergyman."
lichen (n.): c.1600, from Latin lichen, from Greek leichen, originally "what eats around itself," probably from leichein "to lick" (see lick). Originally used of liverwort; the modern sense first recorded 1715. Related: Lichenaceous.
Lichfield: Licitfelda (c.710) "Open Land near Letocetum" (Celtic place name meaning "gray wood") + Old English feld.
licit (adj.): late 15c., from Middle French licite or directly from Latin licitus "lawful," past participle of licere "be allowed, be lawful" (see licence). Related: Licitly; licitness.
lick (v.1): Old English liccian "to pass the tongue over the surface, lap, lick up," from Proto-Germanic *likkon (cf. Old Saxon likkon, Dutch likken, Old High German lecchon, German lecken, Gothic bi-laigon), from PIE imitative base *leigh- (cf. Sanskrit ledhi "he licks," Armenian lizum "I lick," Greek leikhein "to lick," Latin lingere "to lick," Old Irish ligim "I lick," Welsh llwy "spoon"). French lécher is a Germanic loan word.

To lick (someone or something) into shape (1610s) is in reference to the supposed ways of bears:
Beres ben brought forthe al fowle and transformyd and after that by lyckyng of the fader and the moder they ben brought in to theyr kyndely shap. ["The Pylgremage of the Sowle," 1413]
lick (n.): "an act of licking," c.1600, from lick (v.1). Meaning "small portion" is 1814, originally Scottish; hence U.S. colloquial sense. Sense of "place where an animal goes to lick salt" is from 1747. The jazz music sense of "short figure or solo" is by 1922.