What does the name hanzo mean in Japanese?

Hanzo (半蔵; also written as Hanzō and Hanzou) is a name of Japanese origin, and thus does not have a 'meaning' in Japanese.

The separate Kanji that compose a Japanese name hold their own specific meanings, but when composing names hold no meaning.

The Kanji that compose Hanzo, in this case 半蔵 can be separated, and translated to Half (半) and Finance (蔵).