一、指物

His elder brother died of Yellow Jack in the West Indies.

Yellow Jack指医学上的“黄热病”

 the Union Jack

英联合王国国旗

Jacks are common to all that will play

谚：乐器对于所有想要弹奏的人都一样。Jacks是古时类似钢琴的弹奏乐器。

a Jack of straw

稻草人

to make one’s Jack

赚很多钱

二、用来指人
 All the workers want a pay increase, every man Jack of them.

全体工人无一例外地要求增加工资。

every man Jack 或every Jack one是“每个人”、“人人”的意思。

Jack of all trades and master of none

万事皆通而一无所长的人

a Jack on both sides

模棱两可，两面派

Jack at a pinch

临时拉来帮忙的人

All work and no play makes Jack a dull boy.

谚：只工作不玩，聪明的孩子也会变傻。

All shall be well, Jack shall have Jill.

谚：有情人终成着属。

Jack among the maids

 讨好女人的男子

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。

Jack in the water

码头打杂工

cheep Jack

卖廉价货物的小贩

a Jack in office

自命不凡的小官吏，官僚

Jack the lad

（青少年帮派中的）头号人物