Online Etymology Dictionary

law: O.E. lagu (pl. laga, comb. form lah-), from O.N. *lagu "law," collective pl. of lag "layer, measure, stroke," lit. "something laid down or fixed," from P.Gmc. *lagan "put, lay" (see lay (v.)). Replaced O.E. æ and gesetnes, which had the same sense development as law. Cf. also statute, from L. statuere; Ger. Gesetz "law," from O.H.G. gisatzida; Lith. istatymas, from istatyti "set up, establish." Law and order have been coupled since 1796.
law-abiding: 1859, from law + abiding.
lawful: c.1300, laghful; cf. O.N. logfullr (see law).
lawless: c.1200, lawelese (see law + -less) Related: Lawlessness.
lawn (1): "turf, stretch of grass," 1548, laune "glade, open space between woods," from M.E. launde, from O.Fr. lande "heath, moor," from Gaul. (cf. Breton lann "heath"), or from its Gmc. cognate, source of Eng. land (q.v.). The -d perhaps mistaken for an affix and dropped. Sense of "mowed grassy ground" first recorded 1733.
lawn (2): "thin linen or cotton cloth," 1416, from Laon, city in northern France, center of linen manufacture. The town name is O.Fr. Lan, from L. Laudunum, of Celtic origin.
lawn mower: also lawn-mower, 1869, from lawn + mower (see mow (v.)).
Lawrence: see Laurence.
lawsuit: 1620s, from law + suit (n.).
lawyer: late 14c., from M.E. lawe "law" (see law) + -iere. Spelling with -y- first attested 1611.
blue laws: 1781, severe Puritanical code said to have been enacted 18c. in New Haven, Connecticut; of uncertain origin, perhaps from one of the ground senses behind blues, or from notion of coldness. Or perhaps connected to bluestocking in the sense of "puritanically plain or mean" (see bluestocking, which is a different application of the same term; the parliament of 1653 was derisively called the bluestocking parliament). The common explanation that they were written on blue paper is not considered valid; pale blue paper was used for many old U.S. legal documents and there would have been nothing notable about its use in this case.
Boyle's law: named for Irish-born chemist and physicist Robert Boyle (1627-1691), who first published it in 1662.
brother in law: c.1300; also brother-in-law; see brother. In Arabic, Urdu, Swahili, etc., brother-in-law, when addressed to a male who is not a brother-in-law, is an extreme insult, with implications of "I slept with your sister."
bylaw: late 13c., bilage "local ordinance," from O.N. or O.Dan. bi-lagu "town law," from byr "place where people dwell, town, village," from bua "to dwell" + lagu "law." So, a local law pertaining to local residents, or rule of a corporation or association. Sense influenced by by.
claw: O.E. clawu, from P.Gmc. *klawo, from PIE *g(e)l-eu- from base *gel- "to make round, clench." The verb is from O.E. clawian.
cole-slaw: 1794, partial translation of Du. koolsla, from kool "cabbage" (see cole) + sla "salad" (see slaw). Commonly cold slaw in Eng. until 1860s, when M.E. cole "cabbage" was revived.
coleslaw: see cole-slaw.
common law: c.1350, "the customary and unwritten laws of England as embodied in commentaries and old cases" (see common), as opposed to statute law. Phrase common law marriage is attested from 1909.
Delaware: U.S. state, river, Indian tribe, named for the bay, which was named for Baron (commonly "Lord") De la Warr (Thomas West, 1577-1618), first Eng. colonial governor of Virginia. The family name is attested from 1201, from Delaware in Brasted, Kent, probably ult. from de la werre "of the war" (a warrior), from O.Fr. werre/guerre "war."
flaw: early 14c., "snowflake, spark of fire," from O.N. flaga "stone slab, flake" (see flagstone); sense of "defect, fault" first recorded 1580s, first of character, later (c.1600) of material things; probably via notion of a "fragment" broken off. Related: Flawed (early 15c.).
flawless: 1640s, from flaw + -less. Related: Flawlessly.
in-law: 1894, "anyone of a relationship not natural," abstracted from father-in-law, etc.
"The position of the 'in-laws' (a happy phrase which is attributed ... to her Majesty, than whom no one can be better acquainted with the article) is often not very apt to promote happiness." ["Blackwood's Magazine," 1894]
The earliest recorded use of the phrase is in brother-in-law (13c.); the law is Canon Law, which defines degrees of relationship within which marriage is prohibited.
mother-in-law: c.1440, "mother of one's spouse," from mother + in-law (q.v.). Also in early use, "stepmother." In British slang c.1884, mother-in-law was "a mixture of ales old and bitter."
Murphy's law: 1958, used of various pessimistic aphorisms. If there ever was a real Murphy his identity is lost to history. Said to be military originally, and probably pre-dates the earliest printed example (the 1958 citation calls it "an old military maxim").
outlaw (n.): O.E. utlaga "one put outside the law" (and thereby deprived of its benefits and protections), from O.N. utlagi (n.) "outlaw," from utlagr (adj.) "outlawed, banished," from ut "out" + *lagu, pl. of lag "law" (see law).
"[G]if he man to deaðe gefylle, beo he þonne utlah" ["Laws of Edward & Guthrum," c.924]
The verb is from O.E. utlagian. Meaning "one living a lawless life" is first recorded 1880.
Parkinson's Law: 1955 (in the "Economist" of Nov. 19), named for its deviser, British historian and journalist Cyril Northcote Parkinson (1909-1993): "work expands to fill the time available for its completion."
pre-law: "of or pertaining to study in preparation for law school," 1961, Amer.Eng., from pre- + law (school).
scalawag: "disreputable fellow," 1848, Amer.Eng., originally in trade union jargon, of uncertain origin, perhaps an alteration of Scottish scallag "farm servant, rustic" (by influence of wag "habitual joker"). An early recorded sense was "undersized or worthless animal" (1854), which suggests an alteration of Scalloway, one of the Shetland Islands, in allusion to little Shetland ponies. In U.S. history, used from 1862 of anti-Confederate native white Southerners.
scofflaw: 1924, from scoff (q.v.) + law. The winning entry in a national contest during Prohibition to coin a word to characterize a person who drinks illegally, chosen from more than 25,000 entries; the $200 winning prize was split between two contestants who sent in the word separately, Henry Irving Dale and Miss Kate L. Butler. Other similar attempts did not stick, cf. pitilacker (1926), winning entry in Pennsylvania Society for the Prevention of Cruelty to Animals contest to establish a scolding word for one who is cruel to animals (submitted by Mrs. M. McIlvaine Bready of Mickleton, N.J.).
slaw: "sliced cabbage," 1794, from Du. sla, short for salade, from Fr. salade (see salad).
unlawful: c.1300, from un- (1) "not" + lawful. Unlawful assembly is recorded in statutes from late 15c.
wellaway: mid-13c., alteration (by influence of Scandinavian forms) of O.E. wa la wa, lit. "woe, lo, woe!" from wa "woe" (see woe).