To countersign is to put your name on a paper that someone else has already signed. Your name is the second stamp of trust: I have seen this, I stand with it, or I say it is real.

To countersign is countersign指的是 to put your name on a paper把你的名字簽在一份文件上 that someone else has already signed而這份文件已經有別人簽過名了。 Your name is你的簽名是 the second stamp of trust第二個信任的印記： I have seen this我看過這個了、 I stand with it我支持這個、 or I say it is real或是我證實這是真的。

Banks, schools, governments, and old-fashioned offices use it. It is formal. You do not countersign a birthday card.

Banks銀行、 schools學校、 governments政府、 and old-fashioned offices以及老派的辦公室 use it都會用到它。 It is它是 formal正式的用法。 You do not countersign a birthday card你不會去副署一張生日卡。

Though actually the same word can also be a noun in army talk: a special word you must say back, to prove you are not the enemy. That is a different use of the same pieces — a sign given in return — but this entry is the signing of a paper.

Though actually不過其實， the same word同一個字 can also be a noun in army talk在軍隊用語裡也可以當名詞： a special word you must say back一個你必須說回去的特定口令， to prove you are not the enemy用來證明你不是敵人。 That is a different use of the same pieces這是同樣的組成部分的另一種用法 — a sign given in return意思是回應的信號 — but this entry is the signing of a paper但這個條目講的是文件上的簽署。

The second name is not an opposite name; counter- here is 'in return / on the other side of the paper', not 'against'.

The second name is not an opposite name第二個簽名不是相反的名字； counter- here is 'in return / on the other side of the paper'這裡的counter-是「作為回應／在文件的另一面」的意思， not 'against'不是「對抗」的意思。