smart (adj.)youdaoicibaDictYouDict[smart 词源字典]
late Old English smeart "painful, severe, stinging; causing a sharp pain," related to smeortan (see smart (v.)). Meaning "executed with force and vigor" is from c. 1300. Meaning "quick, active, clever" is attested from c. 1300, from the notion of "cutting" wit, words, etc., or else "keen in bargaining." Meaning "trim in attire" first attested 1718, "ascending from the kitchen to the drawing-room c. 1880" [Weekley]. For sense evolution, compare sharp (adj.).

In reference to devices, the sense of "behaving as though guided by intelligence" (as in smart bomb) first attested 1972. Smarts "good sense, intelligence," is first recorded 1968. Smart cookie is from 1948.[smart etymology, smart origin, 英语词源]
street (n.)youdaoicibaDictYouDict
Old English stret (Mercian, Kentish), stræt (West Saxon) "street, high road," from Late Latin strata, used elliptically for via strata "paved road," from fem. past participle of Latin sternere "lay down, spread out, pave," from PIE *stre-to- "to stretch, extend," from root *stere- "to spread, extend, stretch out" (see structure (n.)).

One of the few words 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.

"The normal term in OE for a paved way or Roman road, 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]. Originally of Roman roads (Watling Street, Icknield Street). "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].

Used since c. 1400 to mean "the people in the street;" 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" is from 1967; expression on the street "homeless" is from 1852. Street smarts is from 1971; street-credibility is from 1979. Street-sweeper as an occupation is from 1848.