Online Etymology Dictionary

light-fingered (adj.): "thievish, dexterous in taking," 1540s, from light (adj.1) + finger (n.).
light-headed (adj.): also lightheaded, 1530s, "dizzy," from light (adj.1) + -headed. Of persons or actions, "frivolous, vain, thoughtless," from 1570s. Related: Light-headedness.
light-hearted (adj.): also lighthearted, "cheerful," c. 1400, from light (adj.1) + -hearted. Related: Light-heartedly; light-heartedness.
light-year (n.): also lightyear, "distance light travels in one year" (about 5.87 trillion miles), 1888, from light (n.) + year.
lighten (v.1): "to make less heavy, to lighten a load," mid-14c., lighten, lightnen, from light (adj.1) + -en (1). Figuratively "to make cheerful" from c. 1400. Intransitive sense "become less heavy" is from 1720. Related: Lightened; lightening.
lighten (v.2): "shed light upon, illuminate, make light or bright," early 14c., from light (n.) -en (1). Intransitive meaning "to become brighter" is late 14c.; of faces, expressions, etc., from 1795. Meaning "to flash lightning" is from mid-15c. Related: Lightened; lightening.
lightening (n.): "the shedding of light," mid-14c., verbal noun from lighten (v.2). Meaning "alleviation of weight" (literal and figurative) is from 1520s, from lighten (v.1).
lighter (n.1): type of barge used in unloading, late 15c., agent noun from light (adj.1), with a sense of lightening a load, or else from or modeled on Dutch lichter, from lichten "to lighten, unload," on the same notion. They are used in loading or unloading ships that cannot approach a wharf. Related: Lighterman.
lighter (n.2): "person who lights," 1550s, agent noun from light (v.2). From 1851 of devices or instruments to lighting gas-jets or candles (originally often a simple twist of paper rolled into a tapering tube); from 1895 of mechanical cigarette lighters.
lightfoot (adj.): "speedy, nimble," also a name for a ship or a rabbit, c. 1300 (c. 1200 as a surname) from light (adj.1) + foot (n.).
lighthouse (n.): tower exhibiting lights to warn mariners of rocks, shoals, etc., 1620s, from light (n.) + house (n.).
lighting (n.): "shining, illumination," Old English lihting "shining, illumination; dawn; lightning," from leoht (see light (n.)).
lightless (adj.): Old English leohtleas "dark, receiving no light;" see light (n.) + -less.
lightly (adv.): Old English leohtlice "so as not to be heavy" (of material things, but also of sleep, blows, etc.), from light (adj.1) + -ly (2). Similar formation in Old Frisian lichtelik, Old High German lihtlihho, German leichtlich, Old Norse lettlega (see light (adj.1)). Meaning "frivolously, indifferently" is from early 13c. (compare Old English leohtmodnes "frivolity").
lightness (n.): "quality of having little weight," late Old English lihtnesse, from light (adj.1) + -ness.
lightning (n.): visible discharge of energy between cloud and cloud or cloud and ground, late Old English, "lightning, flash of lightning," verbal noun from lightnen "make bright," or else an extended form of Old English lihting, from leht (see light (n.)). The Old English word also meant "dawn, daybreak," and in Middle English "light of the sun, intense brightness, brilliance; the radiance of Christ." Another Middle English word for it was leven (mid-13c.), of uncertain origin, with no apparent source in Old English. (Old English had ligetung "lightning," from liget "lightning, flash of lightning." "Lightning" also was a specialized sense of lihting "lighting" and beorhtnes "brightness.")

Meaning "cheap, raw whiskey" is attested from 1781, also sometimes "gin." Lightning bug "firefly, phosphorescent beetle" is attested from 1778. Lightning rod from 1790.
lights (n.): "the lungs," c. 1200, literally "the light (in weight) organs," from light (adj.1); also see lung. Obsolete now except in phrases like to knock (someone's) lights out.
lightweight (adj.): also light-weight, 1809, from the noun (1773 in horse-racing, also in pugilism), "man or animal of a certain weight prescribed by rule," from light (adj.1) + weight (n.). Figurative sense of "inconsequential" first attested 1809. The noun sense of "person of little importance or accomplishment" is from 1885.
ligneous (adj.): "woody," 1620s, from French ligneux (16c.) and directly from Latin ligneus, from lignum "wood, firewood" (see ligni-).
ligni-: sometimes ligno-, word-forming element used from late 19c. and meaning "wood," from Latin lignum "wood (for fuel or construction), firewood," from PIE *leg-no-, literally "that which is collected," from root *leg- (1) "to collect, gather." Related: Lignify; lignification.
lignin (n.): organic substance forming the basis of wood-cells, 1821, from Latin lignum "wood" (see ligni-) + chemical suffix -in (2).
lignite (n.): "imperfectly formed coal," 1808, from French, from Latin lignum "wood" (see ligni-). Brown coal that still shows traces of the wood it once was. Probably directly from Lithanthrax Lignius, name given to woody coal by Swedish chemist Johan Gottschalk Wallerius (1709-1785) in 1775.
Liguria: ancient coastal region in what is now Italy and France, including modern Genoa and Nice, from Latin Liguria, from Ligur/Ligus. Related: Ligurian.
like (adj.): "having the same characteristics or qualities" (as another), c. 1200, lik, shortening of y-lik, from Old English gelic "like, similar," from Proto-Germanic *galika- "having the same form," literally "with a corresponding body" (source also of Old Saxon gilik, Dutch gelijk, German gleich, Gothic galeiks "equally, like").

This is a compound of *ga- "with, together" + the Germanic root *lik- "body, form; like, same" (source also of Old English lic "body, corpse;" see lich). Etymologically analogous to Latin conform. The modern form (rather than *lich) may be from a northern descendant of the Old English word's Norse cognate, glikr.

Formerly with comparative liker and superlative likest (still in use 17c.). The preposition (c. 1200) and the adverb (c. 1300) both are from the adjective. As a conjunction, first attested early 16c., short for like as, like unto. Colloquial like to "almost, nearly" ("I like to died laughing") is 17c., short for was like to/had like to "come near to, was likely." To feel like "want to, be in the move for" is 1863, originally American English. Proverbial pattern as in like father, like son is recorded from 1540s.

Meaning "such as" ("A Town Like Alice") attested from 1886. The word has been used as a postponed filler ("going really fast, like") from 1778; as a presumed emphatic ("going, like, really fast") from 1950, originally in counterculture slang and bop talk. Phrase more like it "closer to what is desired" is from 1888.
like (v.): Old English lician "to please, be pleasing, be sufficient," from Proto-Germanic *likjan (source also of Old Norse lika, Old Saxon likon, Old Frisian likia, Dutch lijken "to suit," Old High German lihhen, Gothic leikan "to please"), from *lik- "body, form; like, same."

The sense development is unclear; perhaps "to be like" (see like (adj.)), thus, "to be suitable." Like (and dislike) originally were impersonal and the liking flowed the other way: "The music likes you not" ["The Two Gentlemen of Verona"]. The modern flow began to appear late 14c. (compare please). Related: Liked; liking.
like (n.): "a similar thing" (to another), late Old English, from like (adj.). From c. 1300 as "an equal, a match." The like "something similar" is from 1550s; the likes of is from 1630s.
like-minded (adj.): also likeminded, "with like purpose or disposition," 1520s, from like (adj.) + -minded. One word from 19c.
likeable (adj.): also likable, 1730, a hybrid from like (v.) + -able. Related: Likeableness. Middle English had likeworthy (from Old English licwyrðe "agreeable, acceptable").
likelihood (n.): late 14c., "resemblance, similarity," from likely + -hood. Meaning "probability, state of being like or probable" is from mid-15c.
likeliness (n.): late 14c., "resemblance," also "probability," from likely + -ness.
likely (adj.): c. 1300, "having the appearance of truth or fact," perhaps from Old Norse likligr "likely," from likr "like" (see like (adj.)). Old English had cognate geliclic. Meaning "having the appearance of being strong and capable" is from mid-15c., though now mostly confined to American English; according to OED this sense is perhaps influenced by like (v.). Sense of "good-looking" ("such as may be liked") is from late 15c. Meaning "probable" is attested from late 14c., but said by OED to be now principally in American English. As an adverb, late 14c., from the adjective.
LIKELY. That may be liked; that may please; handsome. In the United States, as a colloquial term, respectable; worthy of esteem; sensible.--Worcester. [Bartlett]
liken (v.): late 13c., "to represent or describe as like, compare," from like (adj.) + -en (1). Related: Likened; likening.
likeness (n.): "representation of an object, that which resembles another, a like shape or form," Old English (Northumbrian) licnes "likeness, similarity; figure, statue, image," shortened from gelicness; see like (adj.) + -ness. Similar formation in Old Saxon gelicnass, Dutch gelijkenis, German Gleichnes.
likes (n.): "predilections, preferences," 1851, plural of like (n.), which was earlier used in the singular in this sense (early 15c.).
likewise (adv.): mid-15c., from the phrase in like wise "in the same manner" (mid-15c.), from like (adj.) + wise (n.).
liking (n.): "fact of being to one's taste," Old English licung, verbal noun from like (v.).
Likud (n.): nationalist coalition party formed in Israel 1973, from Hebrew, literally "union, combination."
Lila: Sanskrit lila "play, sport, amusement."
lilac (n.): 1590s, shrub of genus Syringa with mauve flowers, with French lilac, Spanish lilac from Turkish leylak (the tree reached Western Europe via Istanbul), perhaps from a native Balkan name. Attested from 1791 as a color name; as a scent, from 1895. As an adjective, "pale pinkish-purple," from 1801. Related: Lilaceous.
Lilith: female evil spirit, in medieval Hebrew folklore the first wife of Adam, from Hebrew Lilith, from Akkadian Lilitu, which is connected by folk etymology with Hebrew laylah "night."
Lilliputian (adj.): "diminutive, tiny," literally "pertaining to Lilliput," the fabulous island whose inhabitants were six inches high, a name coined by Jonathan Swift in "Gulliver's Travels" (1726). Swift left no explanation of the origin of the word.
lilt (v.): 1510s, "to lift up" (the voice), probably from West Midlands dialect lulten "to sound an alarm" (late 14c.), a word of unknown origin. Possible relatives include Norwegian lilla "to sing" and Low German lul "pipe;" the whole loose group might be imitative. Sense of "sing in a light manner" is first recorded 1786. Related: Lilted; lilting. As a noun, 1728, "lilting song," from the verb. As "a rhythmical cadence," 1840.
lily (n.): Old English lilie, from Latin lilia, plural of lilium "a lily," cognate with Greek leirion, both perhaps borrowed from a corrupted pronunciation of an eastern Mediterranean word (de Vaan compares Coptic hreri, hleli "lily"). Used in Old Testament to translate Hebrew shoshanna and in New Testament to translate Greek krinon. As an adjective, 1530s, "white, pure, lovely;" later "pale, colorless" (1580s).

Figurative of whiteness, fairness, purity. The Latin word has become the general word in languages across Europe: German lilie, Dutch lelie, Swedish lilja, French lis, Spanish lirio, Italian giglio, Polish lilija, Russian liliya. The French word is contracted from Latin lilius, a rare surviving nominative form in French. In Old French lilie (12c.) also existed. Related: Lilied; lilaceous.

The lily of the valley translates Latin lilium convallium (Vulgate), a literal rendition of the Hebrew term in Song of Solomon ii:1; in modern times the name was applied to a particular plant (Convallaria majalis) apparently first by 16c. German herbalists. Lily pad is from 1834, American English. For gild the lily see gilded.
lily-livered (adj.): "cowardly," 1605, in "Macbeth;" from lily (in its color sense of "pale, bloodless") + liver (n.1), which was a supposed seat of love and passion. A healthy liver is typically dark reddish-brown. Other similar expressions: lily-handed "having white, delicate hands," lily-faced "pale-faced; affectedly modest or sensitive."
lily-pad (n.): "broad leaf of the water-lily," 1834, American English, from lily (n.) + pad (n.).
lily-white (adj.): early 14c., from lily + white (adj.); from 1903 with reference to whites-only segregation; 1961 as "irreproachable."
Lima: Peruvian capital, founded 1535 by Pizarro, from Spanish corruption of Quechua (Inca) Rimak, name of a god and his temple, from rima "to speak" (perhaps a reference to priests who spoke from concealed places in statues of the gods).
lima bean (n.): 1756, associated with Lima, Peru, from which region the plant (Phaseolus lunatus) was introduced to Europe c. 1500. Among the earliest New World crops to be known in the Old World, Simmonds' "Dictionary of Trade" (1858) describes it as "esteemed," but it has the consistency of a diseased dog kidney.
limaceous (adj.): "pertaining to slugs," 1650s, with -ous + Latin limax (genitive limacis) "snail, slug," from Greek leimax, from PIE root *(s)lei- "slime" (see slime (n.)). The Greek word is cognate with Russian slimák "snail," Lithuanian slíekas "earthworm," and the first element in Old English slaw-wyrm "slow-worm."
limb (n.1): "part or member," Old English lim "limb of the body; any part of an animal body, distinct from the head and trunk;" main branch of a tree," from Proto-Germanic *limu- (source also of Old Norse limr "limb," lim "small branch of a tree"), a variant of *liþu- (source of Old English liþ, Old Frisian lith, Old Norse liðr, Gothic liþus "a limb;" and with prefix ga-, source of German Glied "limb, member").

The unetymological -b began to appear late 1500s for no etymological reason (perhaps by influence of limb (n.2)). The Old English plural was often limu; limen and other plural forms in -n lasted into Middle English. Since c. 1400 especially of a leg; in Victorian English this usage was somewhat euphemistic, "out of affected or prudish unwillingness to use the word leg" [Century Dictionary]. However in Old and Middle English, and until lately in dialects, it could mean "any visible body part":
The lymmes of generacion were shewed manyfestly. [Caxton, "The subtyl historyes and fables of Esope, Auyan, Alfonce, and Poge," 1484]
Hence, limb-lifter "fornicator" (1570s). Limb of the law was 18c. derisive slang for a lawyer or police officer. To go out on a limb in figurative sense "enter a risky situation" is from 1897. Alliterative life and limb in reference to the body inclusively is from c. 1200. Obsolete limb-meal (adv.) "limb-from-limb, piecemeal" is from late Old English lim-mælum.