mid-14c., "passage in a house; open passage between buildings; walkway in a garden," from Old French alee (13c., Modern French allée) "a path, passage, way, corridor," also "a going," from fem. of ale, past participle of aler "to go," which is of uncertain origin. It might be a contraction of Latin ambulare "to walk" (Watkins, see amble (v.)), or it might be from Gallo-Roman allari, a back-formation from Latin allatus "having been brought to" [Barnhart]. Compare sense evolution of gate.
Applied by c. 1500 to "long narrow enclosure for playing at bowls, skittles, etc." Used in place names from c. 1500. "In U.S. applied to what in London is called a Mews" [OED], and in American English especially of a back-lane parallel to a main street (1729). To be up someone's alley "in someone's neighborhood" (literally or figuratively) is from 1931; alley-cat (n.) is attested by 1890.
It forms all or part of: abaft; about; alley (n.1) "open passage between buildings;" ambagious; ambassador; ambi-; ambidexterity; ambidextrous; ambience; ambient; ambiguous; ambit; ambition; ambitious; amble; ambulance; ambulant; ambulate; ambulation; ambulatory; amphi-; amphibian; Amphictyonic; amphisbaena; Amphiscians; amphitheater; amphora; amputate; amputation; ancillary; andante; anfractuous; be-; begin; beleaguer; between; bivouac; but; by; circumambulate; embassy; ember-days; funambulist; ombudsman; perambulate; perambulation; preamble; somnambulate; somnambulism; umlaut.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit abhitah "on both sides," abhi "toward, to;" Avestan aibi; Greek amphi "round about;" Latin ambi- "around, round about;" Gaulish ambi-, Old Irish imb- "round about, about;" Old Church Slavonic oba; Lithuanian abu "both;" Old English ymbe, German um "around."
1845, from back slum "dirty back alley of a city, street of poor or low people" (1825), originally a slang or cant word meaning "room," especially "back room" (1812), of unknown origin. Related: slums. Slumscape is from 1947.
1763, "blind alley, dead end," from French impasse "impassable road; blind alley; impasse" (18c.), from assimilated form of in- "not, opposite of" (see in- (1)) + passe "a passing," from passer "to pass" (see pass (v.)). Figurative use (c. 1840) is perhaps from its use in whist. Supposedly coined by Voltaire as a euphemism for cul de sac.
... dans l'impasse de St Thomas du Louvre; car j'appelle impasse, Messieurs, ce que vous appelez cul-de-sac: je trouve qu'une rue ne ressemble ni à un cul ni à un sac: je vous prie de vous servir du mot d'impasse, qui est noble, sonore, intelligible, nécessaire, au lieu de celui de cul, ... (etc.) [Voltaire, "A Messieurs Les Parisiens"]