"one whose occupation is the clearing of soot from chimneys," 1727, from their cry (attested from 1610s); see chimney + sweep (v.). The earlier noun was chimney-sweeper (c. 1500).
Entries linking to chimney-sweep
chimney n.
late 13c., "furnace;" late 14c., "smoke vent of a fireplace, vertical structure raised above a house for smoke to escape to the open air;" from Old French cheminee "fireplace; room with a fireplace; hearth; chimney stack" (12c., Modern French cheminée), from Medieval Latin caminata "a fireplace," from Late Latin (camera) caminata "fireplace; room with a fireplace," from Latin caminatus, adjective of caminus "furnace, forge; hearth, oven; flue," from Greek kaminos "furnace, oven, brick kiln," which is of uncertain origin.
From the persistence of the medial i in OF. it is seen that the word was not an ancient popular word, but a very early adoption of caminata with subsequent phonetic evolution [OED]
Middle English also had native names for it: smokethurl, smokehole (14c.). Jamieson [1808] notes that in vulgar use in Scotland it typically was pronounced "chimley." From the same source are Old High German cheminata, German Kamin, Russian kaminu, Polish komin. Chimney-corner "space beside a fireplace" is from 1570s.
sweep v.
early 14c., "make clean by sweeping with a broom;" mid-14c., "perform the act of sweeping," of uncertain origin, perhaps from a past tense form of Middle English swope "sweep," from Old English swapan "to sweep" (transitive & intransitive); see swoop (v.), or perhaps from a Scandinavian source. Related: Swept; sweeping.
From late 14c. as "hasten, rush, move swiftly and strongly;" also "collect by sweeping." From c. 1400 in transitive sense "drive quickly, impel, move or carry forward by force;" mid-15c. as "clear (something) away." Meaning "win all the events" is 1960, American English. Sense of "pass systematically over in search of something" is from 1966. To sweep (someone) off (his or her) feet "affect with infatuation" is from 1913.