E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
says Francis Crossley, is Luan-dun (Celtic), City of the Moon, and tradition says there was once a temple of Diana (the Moon) where St. Pauls now stands. Greenwich he derives from Grian-wich (City of the Sun), also Celtic. It would fill a page to give a list of guesses made at the derivation of the word London. The one given above is
about the best for fable and mythology. (See AUGUSTA, BABYLON, and LUDS TOWN.)