jack of all trades
【英文解释】person who does a variety of work.
【中文解释】能做多种不同工作的人；杂而不精的人
【短语来源】Jack is a familiar, affectionate or diminutive version of John, perhaps the commonest British name, and occurs in numerous expressions to mean an ordinary man, fellow, chap, etc. Thus jack of all trades(person who does a variety of work), every man jack(everyone without exception), jack-in-the-box and cheap jack(originally Cheap Jack, man who travels about offering bargains for sale, now usually applied to person who sells goods are cheap, shoddy or inferior). Jack is also used as a word for a labouring man(steeplejack) and to express masculinty:a jackass (fool) is originally a male ass. It is a nickname or familiar term of past. A jack is also something taking the place of a man to save labour.
affectionate adj. 挚爱的，亲切的，情深的
diminutive adj. 小巧可爱的，微笑的
chap n. 【口】家伙,小伙子,男人
steeplejack n. 尖塔修建工;高空作业修建工
jackass n, 愚蠢的人，蠢货，傻瓜
ass n. 蠢驴，傻瓜
Jack是John的一个版本，但比John听起来更有感情，含有一种很小巧可爱的意味在里面。Jack可以说是最普通的一个英文名字，大概就跟汉语里的小明、小红差不多。它在很多种表达中都表示普通人。比如说jack of all trades 能做多种工作的人；every man jack 每个人；jack-in-the-box 装在匣内 打开匣盖 自行弹起的玩偶/儿童玩具箱；cheep jack，原写作Cheap Jack，卖廉价货物的小贩，现在多指贩卖便宜、假冒和劣质商品的小贩。
Jack也用于指体力劳动者，如steeplejack 尖塔维修工，高空作业维修工。
Jack的用法其实很多，还可指男性，比如jackass（蠢货；傻瓜）原就是指男滴傻瓜。
同时，jack也可在某些领域表示节省人力的工具，如car-jack就是车辆起重器的意思。
在过去，jack在过去是绰号和很常见的词。
【有例有句】Jack is as good as his master.
谚：伙计不比老板差，卑贱者未必不如高贵者。