under my skin 钻到我的皮下(让我极不舒服)
under the weather 受了风寒
until the cows come home 等到牛回家(空等，白等)
until you are blue in the face 干到脸发青(也是白干)
unwind 放松发条(轻松下来)
up for grabs 大家有份
up in the air 挂在空中(悬而未决)
walk in someone's shoes 穿他的鞋走走看(设身处地，经历相同)
walk on air(高兴得)脚不点地，飘飘然
washed up 像是洗过的(筋疲力尽，力气都放完了)
water off a duck's back 鸭背的水珠(马耳东风)
water under the bridge 桥下的水(逝水，覆水)
when hell freezes over 地狱结冰(绝不可能的事)
weed out 除去杂草(淘汰)
well rounded全 能，全才
when pigs fly 猪飞的时候(绝不可能)
not lift a finger 连手指都不动一动(袖手旁观)
wound up 上足发条(紧张，兴奋)
wrapped around his/her little finger 化为绕指柔(玩弄于股掌之间)
wring his neck 扭断他的脖子
http://meiwen.anslib.com/