Derivation of Name
"Osaka" literally means "large hill" or "large slope." It is unclear when this name gained prominence over Naniwa, but the oldest usage of the name dates back to a 1496 text. Osaka, now written 大阪, was formerly written using a different second kanji as 大坂 prior to 1870. At the time, the partisans for the Meiji Restoration wished to avoid the second kanji being implicitly read as "士反," meaning samurai rebellion. The old writing is still in very limited use to emphasize history, but the second kanji 阪 is now universally considered referring to Osaka city and prefecture only, to distinguish it from homonyms in other Japanese prefectures.
Read more about this topic: Osaka