大坂

Possibly from Old Japanese.

From 大 (ō, “large”) +‎ 坂 (saka, “hill”).

大(おお)坂(さか) • (Ōsaka) ^{←おほさか (Ofosaka)?}

1. obsolete spelling of 大阪 (Ōsaka) (= Osaka): the capital city of Osaka Prefecture, Japan
2. a surname

Due to confusion of the second kanji 坂, it was superseded with 阪 during the early Meiji period.

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)

The saka changes to zaka as an instance of rendaku (連濁).

大(おお)坂(ざか) • (Ōzaka) ^{←おほざか (Ofozaka)?}

1. (rare) obsolete spelling of 大阪 (Ōzaka), former name of Osaka: the capital of Osaka Prefecture, Japan

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)

大(だい)坂(さか) • (Daisaka) ^{←だいさか (Daisaka)?}

1. a surname

Attested in the Kojiki (720 CE).

From 大 (opo, “large”) +‎ 坂 (saka, “hill”).

大坂 (Oposaka) (kana おほさか)

1. Oposaka (a hill downsloping from Yamato to Kawachi provinces, in modern Japan)

• Japanese: 大阪, 大坂 (Ōsaka)