strath (n.)

"horizontal layer," 1590s, from a Modern Latin special use of Latin stratum "thing spread out, coverlet, bedspread, horse-blanket; pavement," noun uses of neuter of stratus "prostrate, prone," past participle of sternere "to spread out, lay down, stretch out" (from nasalized form of PIE root *stere- "to spread").

Middle English strete, "road in a city or town," also "road from one city or town to another," from Old English stret (Mercian, Kentish), stræt (West Saxon) "street, high road," from Late Latin strata, used elliptically for via strata "paved road." Latin strata is fem. past participle of sternere "lay down, spread out, pave," from PIE *stre-to- "to stretch, extend" (from nasalized form of PIE root *stere- "to spread").

One of the rare words that has been in use in England continuously from Roman times. An early and widespread Germanic borrowing (Old Frisian strete, Old Saxon strata, Middle Dutch strate, Dutch straat, Old High German straza, German Strasse, Swedish stråt, Danish sträde "street"). The Latin is also the source of Spanish estrada, Old French estrée, Italian strada.

It was the usual Old English term for Roman roads (Watling Street, Icknield Street), "later extended to other roads, urban streets, and in SE dialects to a street of dwellings, a straggling village or hamlet" [Cambridge Dictionary of English Place-Names]. "In the Middle Ages, a road or way was merely a direction in which people rode or went, the name street being reserved for the made road" [Weekley].

It has been used since late 14c. to mean "the people in the street, inhabitants of a street;" the modern sense of "the realm of the people as the source of political support" dates from 1931. The street for an especially important street is from 1560s (originally of London's Lombard-street). Man in the street "ordinary person, non-expert" is attested from 1831.

Street people "the homeless, vagrants" is from 1967; the expression on the street "homeless" is from 1852 (by 1728 of women, with implications of prostitution). Street smarts is from 1971; street-credibility is from 1979. Street-preacher is by 1722, originally of Methodists (and sometimes Quakers); street-preaching is by 1838, distinguished by the Methodists from field-preaching. Street-sweeper as an occupation is from 1848.

*sterə-, also *ster-, Proto-Indo-European root meaning "to spread."

It forms all or part of: consternate; consternation; construct; construction; destroy; destruction; industry; instruct; instruction; instrument; obstruct; obstruction; perestroika; prostrate; sternum; sternocleidomastoid; strain (n.2) "race, stock, line;" stratagem; strategy; strath; strato-; stratocracy; stratography; stratosphere; stratum; stratus; straw; stray; street; strew; stroma; structure; substrate; substratum; substructure.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit strnoti "strews, throws down;" Avestan star- "to spread out, stretch out;" Greek stronymi "strew," stroma "bedding, mattress," sternon "breast, breastbone;" Latin sternere "to stretch, extend;" Old Church Slavonic stira, streti "spread," strana "area, region, country;" Russian stroji "order;" Gothic straujan, Old High German strouwen, Old English streowian "to sprinkle, strew;" Old English streon "strain," streaw "straw, that which is scattered;" Old High German stirna "forehead," strala "arrow, lightning bolt;" Old Irish fo-sernaim "spread out," srath "a wide river valley;" Welsh srat "plain."