nomenclature - Why is it ACETone?

Acet* indicates Ethyl, but does not offer two Carbon atoms, but three.

Acetaldehyde is Ethanal, Acetic acid is Ethanoic acid, but Aceton is Propanon (yes, I'm aware that there is no Ethanon).

Why is Acetone called Acetone?

Answer

Here's a link to the first page of a book entitled, "The History of Acetone, 1600-1850" by Mel Gorman. The author points out that acetone was known in the Middle Ages and was frequently produced by heating dry lead acetate. I suspect that the "acetate" (or whatever the Latin, French or German term was) root stuck and then it was just modified a bit - to acetone - to make it distinct.