Rogrund
Antti Sivén
"There are many guesses how this name [Summicron] came about, a popular one being that the "summi" came from "summit" (summit means the highest point of a hill or mountain; the highest attainable level of achievement) while the "cron" came from "chroma" (ie. for colour). Not so: The name (Summi)cron was used because the lens used Crown glass for the first time, which Leitz bought from Chance Brothers in England. The first batch of lenses were named Summikron (Crown = Krone in Deutsch)."
(from http://www.overgaard.dk/leica_lens_compendium.html)