山口 Traditional form: 山口 Pinyin (reading): Shānkǒu Definitions: Yamaguchi (Japanese surname and place name) Yamaguchi prefecture in the southwest of Japan's main island Honshū 本州 ( Běnzhou) Characters: 山 - mountain, hill, peak 口 - mouth; entrance, gate, opening Traditional characters: 山 - mountain, hill, peak 口 - mouth; entrance, gate, opening