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.| stack (n.) c. 1300, "pile, heap, or group of things," from a Scandinavian source akin to Old Norse stakkr "haystack" (cognate with Danish stak, Swedish stack "heap, stack"), from Proto-Germanic stakon- "a stake," from PIE stog- (source also of Old Church Slavonic stogu "heap," Russian stog "haystack," Lithuanian stokas "pillar"), variant of root steg- (1) "pole, stick". Meaning "set of shelves on which books are set out" is from 1879. Used of the chimneys of factories, locomotives, etc., since 1825. Of computer data from 1960.