U 开头单词
understandability n.易懂性；可理解性
understand trap 機警，聰明
understand tacitly 心領神會
understand his kind father 理解他好心的父親
understand clearly 清楚地懂得 清楚地了解
understand vt. 理解；懂；獲悉；推斷；省略；明白 vi. 理解；懂得；熟悉
understain 淺染
understaffed adj.人員不足的
undersquare 下耳戳
underspend vt.vi；
underspeed n.速度不足(降低速度)
undersonic adj.次聲的
undersong n.伴唱之歌；重曡句；隱匿之意義
undersole 大底,鞋底
undersold v. 低價出售(拋售； 售價比 ... 低)
undersoil n.下層土(底土)
undersocialization 社會化不足
underslung worm [能源科學技術]下置式蝸杆