underdeveloped /ˈʌndədiˈveləpt/ adj. 1. (国家等)经济不发达的；发育不全的：underdeveloped nations不发达国家；underdeveloped kidneys发育不全的肾 It’s in the underdeveloped eastern region of the country that the biggest problems exist.最大的问题存在于这个国家贫穷落后的东部地区。2. 显影不足的：The prints were underdeveloped.这些照片显影不足。