最盛 さいせい Meanings の-adjective peak (of prosperity, popularity, etc.); height; prime See also: 最盛期 (さいせいき). Kanji 最 most. Read as サイ. 盛 heap up. Read as セイ. Words containing 最盛 最盛期 (さいせいき) golden age Jinuma: Japanese Dictionary · Word lists