Online Etymology Dictionary

light (v.2): "to illuminate, fill with brightness," Old English lyhtan, common Germanic (cf. Old Saxon liohtian, Old High German liuhtan, German leuchten, Gothic liuhtjan "to light"), from source of from light (n.). Related: Lighted; lighting.
light (adj.2): "not dark," Old English leoht, common Germanic (cf. Old Saxon and Old High German lioht, Old Frisian liacht, German licht "bright," from the source of Old English leoht (see light (n.)). Meaning "pale-hued" is from 1540s.
light bulb (n.): also lightbulb, 1884, from light (n.) + bulb.
light year (n.): also light-year, lightyear, "distance light travels in one year," 1888, from light (n.) + year.
light-fingered (adj.): "thievish," 1540s, from light (adj.1) + finger.
light-headed (adj.): also lightheaded, "dizzy," 1530s; from light (adj.1) + head (n.). Related: Light-headedness.
light-hearted (adj.): also lighthearted, "cheerful," c.1400, from light (adj.1) + hearted. Related: Light-heartedly; light-heartedness.
lighten (v.1): "to make less heavy," figuratively "to make cheerful," mid-14c., from light (adj.1) + -en (1). Related: Lightened; lightening.
lighten (v.2): "shed light upon, illuminate, brighten," early 14c., from light (n.) -en (1). Meaning "to grow brighter" is late 14c. Of faces, expressions, etc., from 1795. 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): "barge," late 15c., agent noun from light (adj.1), with a sense of lightening a load, or else from Dutch lichter, from lichten "to lighten, unload," on the same notion. They are used in loading or unloading ships that cannot approach a wharf.
lighter (n.2): "person who lights," 1550s, agent noun from light (v.2).
lighthouse (n.): 1620s, from light (n.) + house (n.).
lighting (n.): "shining, illumination," Old English lihting, from leoht (see light (n.)).
lightless (adj.): Old English leohtleas; see light (n.) + -less.
lightly (adv.): Old English leohtlice "so as not to be heavy" (of material things, but also of sleep, blows, etc.); cognate with Old Frisian lichtelik, Old High German lihtlihho, German leichtlich, Old Norse lettlega (see light (adj.1)). Meaning "frivolously, indifferently" is from early 13c.
lightness (n.): "quality of having little weight," late Old English, from light (adj.1) + -ness.
lightning (n.): late 13c., present participle of lightnen "make bright," extended form of Old English lihting, from leht (see light (n.)). Meaning "cheap, raw whiskey" is attested from 1781, also sometimes "gin." Lightning bug 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, 1773 in horse-racing, also in pugilism; from light (adj.1) + weight. Figurative sense of "inconsequential" first attested 1809.
ligneous (adj.): "woody," 1620s, from French ligneux and directly from Latin ligneus, from lignum "wood, firewood" (see ligni-).
ligni-: word-forming element meaning "wood," from Latin lignum "wood, firewood," from PIE *leg-no-, literally "that which is collected," from root *leg- "to collect" (see lecture (n.)).
lignin (n.): 1822, 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.
like (adj.): "having the same characteristics or qualities" (as another), Middle English shortening of Old English gelic "like, similar," from Proto-Germanic *galika- "having the same form," literally "with a corresponding body" (cf. Old Saxon gilik, Dutch gelijk, German gleich, Gothic galeiks "equally, like"), a compound of *ga- "with, together" + Germanic base *lik- "body, form; like, same" (cf. Old English lic "body," German Leiche "corpse," Danish lig, Swedish lik, Dutch lijk "body, corpse"). Analogous, etymologically, 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. 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 (n.): c.1200, "a similar thing" (to another), from like (adj.).
like (v.): Old English lician "to please, be sufficient," from Proto-Germanic *likjan (cf. Old Norse lika, Old Frisian likia, Old High German lihhen, Gothic leikan "to please"), from *lik- "body, form; like, same."

The basic meaning seems to be "to be like" (see like (adj.)), thus, "to be suitable." Like (and dislike) originally flowed the other way: It likes me, where we would say I like it. The modern flow began to appear late 14c. (cf. please).
likeable (adj.): also likable, 1730, from like (v.) + -able. Related: Likeableness.
likelihood (n.): late 14c., "resemblance, similarity," from likely + -hood. Meaning "probability" is from mid-15c.
likely (adj.): c.1300, 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" is from late 15c. Meaning "probably" is attested from late 14c., now principally in American English.
LIKELY. That may be liked; that may please; handsome. In the United States, as a colloquial term, respectable; worthy of esteem; sensible.--Worcester. [Bartlett]
As an adverb, late 14c., from the adjective.
likeminded (adj.): also like-minded, 1520s, from like (adj.) + minded. One word from 19c.
liken (v.): late 13c., "to represent as like," from like (adj.) + -en (1). Related: Likened; likening.
likeness (n.): Old English (Northumbrian) licnes "likeness, similarity; figure, statue, image," shortened from gelicness; see like (adj.) + -ness.
likes (n.): "predilections, preferences," 1851, plural of like (n.); earlier used in 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.).
Likud (n.): nationalist coalition party formed in Israel 1973, from Hebrew, literally "union, combination."
lilac (n.): 1620s, from French lilac "shrub of genus Syringa with mauve flowers," from Spanish lilac, from Arabic lilak, from Persian lilak, variant of nilak "bluish," from nil "indigo" (cf. Sanskrit nilah "dark blue"), of uncertain origin. As a color name, attested from 1791; 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 Akkad. 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 late 14c. West Midlands dialect lulten "to sound an alarm," of unknown origin. Possible relatives include Norwegian lilla "to sing" and Low German lul "pipe." It is possible that the whole loose group is 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 "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 Egyptian word. 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).

Also from the Latin word are German lilie, French lis, Spanish lirio, Italian giglio. The lily of the valley translates Latin lilium convallium (Vulgate), a literal rendition of the Hebrew term in Song of Solomon ii:1. It apparently was applied to a particular plant (Convallaria majalis) first by 16c. German herbalists. Lily pad is from 1834, American English.
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.
lily-white (adj.): early 14c., from lily + white; from 1903 with reference to whites-only segregation; 1964 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, joint, main branch of a tree," from Proto-Germanic *limu- (cf. Old Norse limr "limb," lim "small branch of a tree"), a variant of *liþu- (cf. Old English liþ, Old Frisian lith, Old Norse liðr, Gothic liþus "a limb;" and with prefix ga-, source of German Glied "limb, member"), from PIE root *lei- "to bend, be movable, be nimble." The parasitic -b began to appear late 1500s for no etymological reason (perhaps by influence of limb (n.2)). 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). To go out on a limb in figurative sense "enter a risky situation" is from 1897. Life and limb in reference to the body inclusively is from c.1200.
limb (n.2): late 14c., "edge of a quadrant or other instrument," from Latin limbus "border, hem, fringe, edge," of uncertain origin. Klein suggests cognate with Sanskrit lambate "hangs down," and English limp. But Tucker writes that "the sense appears to be that of something which twists, goes round, or binds ... not of something which hangs loose," and suggests cognates in Lithuanian linta "ribbon," Old Norse linnr "whether." Astronomical sense of "edge of the disk of a heavenly body" first attested 1670s.
limbate (adj.): "edged, bordered," 1826, from Late Latin limbatus, from Latin limbus (see limb (n.2)).
limber (adj.): "pliant, flexible," 1560s, of uncertain origin, possibly from limb (n.1) on notion of supple boughs of a tree [Barnhart], or from limp "flaccid" [Skeat], or somehow from Middle English lymer "shaft of a cart" (see limber (n.)), but the late appearance of the -b- in that word argues against it. Related: Limberness. Dryden used limber-ham (see ham (n.1) in the "joint" sense) as a name for a character "perswaded by what is last said to him, and changing next word."