未発達の 〔ほとんど発達していない〕undeveloped;〔発達がまだ不十分の〕underdeveloped

    • 未発達の文化
    • an undeveloped civilization
    • あの子は心も体も未発達だ
    • The child is underdeveloped both in mind and body./The child has not fully developed in mind or in body.