(1)解(松)开(untie or loosen)[T+n]：～a parcel/some knitting拆包/织物;～the dress/the tie/the buttons/the knot (in this string)/the string (round a parcel) 解开衣服/领带/钮扣/(绳)结/(扎包)绳;(zip/shoelace)be undone(拉锁/鞋带)开了;〖同〗 open，unfasten，unlock，unfold，unknot，unbutton;〖反〗tie，close，fasten，knot，button;

(2)使完全无效(白做);取消(reverse the effect of; cancel)[T+n]：～sb's whole day's work in 10 minutes 10分钟工夫使他人一天的活都白干了;What is done cannot be undone. 覆水难收。That one mistake undid all the good work of the predecessor/the past three months. 前任/三个月的出色工作被那个错误一笔勾销。It's almost impossible to～the harm you've done. 你造成的伤害几乎不可能消除。The evil that he did can never be undone. 他的罪孽是洗刷不掉的。〖同〗cancel，erase，wipe out;〖反〗do，accomplish，produce;

(3)毁掉……的声誉(前程)(ruin， esp the reputation of)[T+n， 通常pass]：He knew he would be undone if there was a public scandal. 他知道如果丑闻传开，他就名声扫地了。The gossip is bound to～his candidacy. 流言蜚语注定要毁掉他的候选人的资格。His plot has been discovered and he is undone. 阴谋被发现后他的名声扫地。〖同〗ruin，destroy;〖反〗help，aid;

← do vt;

→un′doing n 毁灭，垮台;un′done adj 解开的;未完成的;un′doer n破坏者