Dictionary/成約せいやくSeiyaku成約 (Seiyaku) is a Japanese noun meaning “conclusion of a contract”.Meaningsnoun, suru verb, intransitive verbconclusion of a contractKanji in 成約成turn into約promiseRelated words約束promise成る程I see行き成りabruptly可也considerably成功success成すto form契約contract要約summary完成completion成長growth約approximately予約reservation