Online Etymology Dictionary

lavish (v.): "spend or bestow profusely," 1540s, from lavish (adj.). Related: Lavished; lavisher; lavishing.
law (v.): 1640s, "to litigate," from law (n.). Old English had lagian "make a law, ordain." Related: Lawed; lawing.
law (n.): Old English lagu (plural laga, comb. form lah-) "ordinance, rule prescribed by authority, regulation; district governed by the same laws;" also sometimes "right, legal privilege," from Old Norse *lagu "law," collective plural of lag "layer, measure, stroke," literally "something laid down, that which is fixed or set" from Proto-Germanic *lagam "put, lay," from PIE root *legh- "to lie, lay" (see lay (v.)). Identical with lay (n.2) as "that which is set or established."

Rare in Old English, it ousted the more usual ae and also gesetnes, which also were etymologically "something placed or set." Compare also statute, from Latin statuere; German Gesetz "law," from Old High German gisatzida; Lithuanian istatymas, from istatyti "set up, establish."

In physics, "a proposition which expresses the regular order of things," from 1660s. Law and order have been coupled since 1796. To lay down the law (1752) is pleonastic (the "law" in the figure is biblical law, laid down from the pulpit). Poor laws provided for the support of paupers at public expense; sumptuary laws restrained excesses in apparel, food, or luxuries.

It is more common for Indo-European languages to use different words for "a specific law" and for "law" in the general sense of "institution or body of laws," for example Latin lex "a law," ius "a right," especially "legal right, law." Words for "a law" are most commonly from verbs for "to put, place, set, lay," such as Greek thesmos (from tithemi "to put, place"), Old English dom (from PIE *dhe- "to put, place, set"), Lithuanian istatymas (from statyti "cause to stand, set"), Polish ustawa (from stać "stand").

Words for "law" in the general sense mostly mean etymologically "what is right" and often are connected with adjectives for "right" (themselves often figurative uses of words for "straight," "upright," "true," "fitting," or "usage, custom." Such are Greek nomos (numismatic); French droit, Spanish derecho, from Latin directus; Polish prawo, Russian pravo (from Old Church Slavonic pravŭ "straight," in the daughter languages "right"); also Old Norse rettr, Old English riht, Dutch recht, German Recht (see right (adj.1)).
law-abiding (adj.): "obedient to the laws," 1828, from law (n.) + abiding.
law-breaker (n.): also lawbreaker, mid-15c., from law (n.) + agent noun from break (v.). Old English had lahbreca.
law-giver (n.): also lawgiver, "one who makes or enacts a code of laws," late 14c., from law (n.) + agent noun from give (v.).
lawful (adj.): c. 1300, laghful, "rightful, supported by law" (of sanctions, etc.); see law (n.) + -ful. Meaning "allowed by law" is late 14c. Similar construction in Old Norse logfullr. Old English had lahlic. Related: Lawfully; lawfulness.
lawless (adj.): c. 1200, lawelese "uncontrolled by law of any kind," from law (n.) + -less. Meaning "illegal" is from c. 1300. Related: Lawlessly; lawlessness.
lawmaker (n.): also law-maker, "legislator," late 15c., from law (n.) + maker.
lawman (n.): 1530s, "lawyer," from law (n.) + man (n.). Meaning "law-enforcement officer" is from 1865. Old English had lahmann "an official or declarer of the law, one acquainted with the law and qualified to declare it," a word from Old Norse. There is an Anglo-Latin lagamannus "magistrate" from early 12c., hence the proper name of Layamon, author of the "Brut."
lawn (n.1): "turf, stretch of grass," 1540s, laune "glade, open space in a forest or between woods," from Middle English launde (c. 1300), from Old French lande "heath, moor, barren land; clearing" (12c.), from Gaulish (compare Breton lann "heath"), or from a cognate Germanic word, from Proto-Germanic *landam-, source of English land (n.). The -d perhaps was mistaken for an affix and dropped. Sense of "grassy ground kept mowed" first recorded 1733. Lawn-tennis is from 1884.
lawn (n.2): "thin linen or cotton cloth," early 15c., probably from Laon, city in northern France, a center of linen manufacture. The town name is Old French Lan, from Latin Laudunum, of Celtic origin. For form evolution, compare fawn (n.) from faon. Lawn sleeves (1630s) were emblematic of Anglican bishops.
lawn-mower (n.): 1853 as a type of machine to cut grass, from lawn (n.1) + mower. Originally pushed by hand or drawn by horses, later also powered by a motor.
lawn-sprinkler (n.): 1872, from lawn (n.1) + sprinkler.
Lawrence: see Laurence.
lawrencium (n.): 1961, Modern Latin, from the name of Ernest O. Lawrence (1901-1958), U.S. physicist, cyclotron pioneer and founder of the lab where it was discovered. With metallic element ending -ium.
lawsuit (n.): 1620s, from law (n.) + suit (n.).
lawyer (n.): late 14c. lauier, lawer, lawere (mid-14c. as a surname), "one versed in law, one whose profession is suits in court or client advice on legal rights," from Middle English lawe "law" (see law) + -iere. Spelling with -y- predominated from 17c. (see -yer). In the New Testament (Luke xiV:3, etc.) "interpreter of Mosaic law." Old English had lahwita, with wita "sage, wise man; adviser councilor." Related: Lawyerly.
lax (adj.): c. 1400, "loose" (in reference to bowels), from Latin laxus "wide, spacious, roomy," figuratively "loose, free, wide" (also used of indulgent rule and low prices), from PIE *lag-so-, suffixed form of root *(s)lēg- "to be slack, be languid" (source also of Greek legein "to leave off, stop," lagos "hare," literally "with drooping ears," lagnos "lustful, lascivious," lagaros "slack, hollow, shrunken;" Latin languere "to be faint, weary," languidis "faint, weak, dull, sluggish, languid").

In English, of rules, discipline, etc., from mid-15c. Related: Laxly; laxness. A transposed Vulgar Latin form yielded Old French lasche, French lâche. The laxists, though they formed no avowed school, were nonetheless condemned by Innocent XI in 1679.
lax (n.): "salmon," from Old English leax (see lox). Cognate with Middle Dutch lacks, German Lachs, Danish laks, etc.; according to OED the English word was obsolete except in the north and Scotland from 17c., reintroduced in reference to Scottish or Norwegian salmon.
lax (n.): 1951 as an abbreviation of lacrosse.
laxative (adj.): late 14c., "causing relaxation or looseness," from Old French laxatif (13c.), from Medieval Latin laxativus "loosening," from Latin laxat-, past participle stem of laxare "loosen," from laxus "loose, lax" (see lax). The noun meaning "a laxative medicine, a medicine that relieves constipation by relaxing the intestines" is from late 14c.
laxity (n.): 1520s, from Middle French laxité, from Latin laxitatem (nominative laxitas) "width, spaciousness," from laxus "loose, lax" (see lax). An earlier noun was laxation (late 14c.). Laxness is from 1630s.
lay (v.): "to cause to lie or rest," Old English lecgan "to place on the ground (or other surface); place in an orderly fashion," also "put down" (often by striking), from Proto-Germanic *lagjan (source also of Old Saxon leggian, Old Norse leggja, Old Frisian ledza, Middle Dutch legghan, Dutch leggen, Old High German lecken, German legen, Gothic lagjan "to lay, put, place"). This is a causative form of the ancient Germanic verb that became modern English lie (v.2).

Meaning "have sex with" first recorded 1934, in U.S. slang, probably from sense of "bring forth and deposit" (which was in Old English, as in lay an egg, lay a bet, etc.), perhaps reinforced by to lie with, a phrase frequently met in the Bible. To lay for (someone) "await a chance at revenge" is from late 15c.; lay low "stay inconspicuous" is from 1839; to lay (someone) low preserves the secondary Old English sense.
lay (n.1): "short song," mid-13c., from Old French lai "song, lyric," of unknown origin. Perhaps from Celtic (compare Irish laid "song, poem," Gaelic laoidh "poem, verse, play") because the earliest verses so called were Arthurian ballads, but OED finds this "out of the question" and prefers a theory which traces it to a Germanic source, such as Old High German leich "play, melody, song."
lay (n.2): 1550s, "act of laying," from lay (v.). From 1580s as "a wager." Meaning "relative position, direction, etc.,; way in which something is laid" (as in lay of the land) first recorded 1819. Slang meaning "line of business" is from 1707. Meaning "woman perceived as available for sex" is attested from 1930, but there are suggestions of it in stage puns from as far back as 1767.
lay (adj.): "uneducated, non-professional; non-clerical," early 14c., from Old French lai "secular, not of the clergy" (12c., Modern French laïque), from Late Latin laicus, from Greek laikos "of the people," from laos "(the common) folk, the people, the crowd; the military; a tribe," in the New Testament especially "the Jewish people," also "the laity," a word of unknown origin. Beekes writes that it is "most often connected with" Hittite lahh- "campaign" and Old Irish laech "warrior," but that the form "is rather Pre-Greek, and has a Pre-Greek suffix -it(o)-. In Middle English, contrasted with learned, a sense revived 1810 in contrast to expert. Laic is a more modern borrowing directly from Late Latin.
lay-away (n.): also lay-away, 1961 in reference to a system of payments for reserved merchandise, from the verbal phrase (attested from c. 1400 as "to put away," especially "place in store for future use"); see lay (v.) + away (adv.). Earlier in the same sense, as an adjective, was Australian lay-by (1930).
layabout (n.): "habitual loafer," 1932, from the verbal phrase; see lay (v.) + about (adv.). One who "lays about" the house, etc.
layer (v.): 1832, in gardening, as a method of plant propagation, from layer (n.). Meaning "to form into layers" is from 1852. Related: Layered; layering.
layer (n.): late 14c., "one who or that lays" (especially stones, "a mason"), agent noun from lay (v.). Passive sense of "a thickness of some material laid over a surface" is first recorded 1610s, but because the earliest English use was in cookery this is perhaps from French liue "binding," used of a thickened sauce. Of hens from 1707. Layer cake attested from 1875.
layette (n.): "newborn baby's outfit," 1839, from French layette, properly the box in which it comes, subsequently transferred to the linen, from Middle French layette "chest of drawers," from laie "drawer, box," from Middle Dutch laeye, which is related to lade, load (v.).
laying (n.): early 14c., verbal noun from lay (v.).
layman (n.): "non-cleric," early 15c., from lay (adj.) + man (n.). Similar formation in Old Frisian lekman, Danish lægmand. Meaning "outsider, unprofessional person, non-expert" (especially in regards to law or medicine) is from late 15c. Related: Laymen.
layoff (n.): also lay-off, lay off; 1889, "rest, relaxation, respite;" from the verbal phrase; see lay (v.) + off (adv.). Via seasonal labor with periodic inactivity, it came to have a sense of "temporary release from employment," and by 1960s was being used somewhat euphemistically for permanent releases of masses of workers by employers. The verbal phrase lay off is attested from 1841 (colloquial) as "stop working, be idle" (intransitive); 1892 as "dismiss" (an employee); meaning "stop disturbing" is from 1908. Its oldest sense is "remove and lay aside, rid oneself of" (1590s).
layout (n.): also lay-out, "configuration, arrangement," 1852, from the verbal phrase; see lay (v.) + out (adv.). Meaning "rough design of a printing job" is from 1910. The verbal phrase is attested from c. 1400 as "expose to view, show, set forth;" mid-15c. as "to expend, lavish." The meaning "prepare (a corpse) for burial" is from 1590s and is said to be the source of the figurative sense "knock out; kill."
layover (n.): also lay-over, "a stop overnight," 1873, from the verbal phrase; see lay (v.) + over (adv.). Earlier as "a cloth laid over a table-cloth" (1777). The verbal phrase is from 1530s as "to overlay."
layperson (n.): 1972, gender-neutral version of layman.
layup (n.): also lay-up, 1927, "temporary period out of work," from the verbal phrase; see lay (v.) + up (adv.). Compare layoff. Basketball shot so called by 1955, short for lay-up shot (1947). The verbal phrase is attested from mid-14c. as "store away," 1550s as "confine to one's bed or room" (of illness); of ships in docks, 1660s. Related: Laid-up.
laywoman (n.): 1520s, from lay (adj.) + woman; probably modeled on layman.
lazar (n.): "filthy beggar, leper," c. 1300, from Medieval Latin lazarus "leper," from Lazarus (q.v.), the name of the beggar in the biblical parable. Sometimes also lazard, with pejorative suffix.
lazaretto (n.): "house for reception of lepers and diseased poor persons," 1540s, from Italian lazareto "place set aside for performance of quarantine" (especially that of Venice, which received many ships from plague-infested districts in the East), from the Biblical proper name Lazarus (q.v.). Meaning "building set apart for quarantine" is c. 1600 in English. The word in Italian was perhaps influenced by the name of another hospital in Venice, that associated with the church of Santa Maria di Nazaret. Sometimes Englished as lazaret; also known as lazar house (1520s).
Lazarus: Biblical character (Luke xvi:20), the poor man covered in sores; his name was extended in medieval usage to "any poor and visibly diseased person" (compare lazar, mid-14c., "one deformed and nauseous with filthy and pestilential diseases" [Johnson]). The name is from a Greek rendition of Hebrew El'azar, literally "(he whom) God has helped."
laze (v.): 1590s, back-formation from lazy. Related: Lazed; lazing.
lazily (adv.): 1580s, from lazy + -ly (2).
laziness (n.): 1570s, from lazy + -ness.
lazuli (n.): 1789, short for lapis lazuli.
lazy (adj.): 1540s, laysy, of persons, "averse to labor, action, or effort," a word of unknown origin. In 19c. thought to be from lay (v.) as tipsy from tip. Skeat is responsible for the prevailing modern view that it probably comes from Low German, from a source such as Middle Low German laisch "weak, feeble, tired," modern Low German läösig, early modern Dutch leuzig, all of which may go back to the PIE root *(s)leg- "slack." According to Weekley, the -z- sound disqualifies a connection with French lassé "tired" or German lassig "lazy, weary, tired." A supposed dialectal meaning "naught, bad," if it is the original sense, may tie the word to Old Norse lasenn "dilapidated," lasmøyrr "decrepit, fragile," root of Icelandic las-furða "ailing," las-leiki "ailment."

Replaced native slack, slothful, and idle as the usual word expressing the notion of averse to work. Lazy Susan is from 1917. Lazy-tongs is from 1785, "An instrument like a pair of tongs for old or very fat people, to take anything off the ground without stooping" [Grose, "Dictionary of the Vulgar Tongue"]. In his 1788 edition, Grose has lazy man's load: "Lazy people frequently take up more than they can safely carry, to save the trouble of coming a second time."
lazybones (n.): "idler," colloquial, 1590s, from lazy + plural of bone (n.). Another form was lazyboots (1831).
lazzarone (n.): "Italian beggar," 1792, Italian, augmentative of lazzaro "a beggar, leper," from Lazarus (q.v.).