Fetching details from the dictionary...
not only ... (but also); not merely; as well as
furthermore; besides; moreover; what's more
彼は英語のみならずフランス語も話せる。
He can speak not only English but also French.
国内のみならず海外でも有名になった。
He became famous not only domestically but also overseas.
子供のみならず大人も楽しめる映画だ。
It is a movie that not only children but also adults can enjoy.