十分 (jūbun) means "enough," "sufficient," or "plenty." You use it to say that something is in an adequate amount or degree, or that something has been done completely. It indicates that there is no need for more. For example, 「時間は十分あります。」 (There is enough time.)

必要な量や程度が足りていることです。これ以上いらない、という意味でも使います。「時間は十分あります。」