A self-feeding digesting furnace that maintained a uniform and durable heat and was used by alchemists. The word comes from Arabic at-tannūr, the oven, from Aramaic tannūr, oven. I wonder if tandoori is related?
From the story “Actors” in the collection Dictation by Cynthia Ozick, page 79.
The usage in context here is pretty undistinguished, as the word appears in a list of words that the author of crossword puzzles happens to know. It’s not really worth quoting.