Tacit describes an agreement, an understanding, approval, or support that is real but was never actually said out loud. Everyone involved knows it, but nobody put it into words. If your boss sees you leaving early every Friday and says nothing for a year, you have her tacit approval — she never said 'yes, go ahead', but her silence has done the work of a yes.

Tacit describes an agreement, an understanding, approval, or supportTacit 用來形容一種協議、共識、同意或支持 that is real but was never actually said out loud這種東西是真實存在的，但從來沒有真正被說出口。Everyone involved knows it每個相關的人都知道, but nobody put it into words但沒有人把它說出來。If your boss sees you leaving early every Friday如果你老闆看到你每個星期五都提早下班 and says nothing for a year而且一整年都沒說什麼, you have her tacit approval那你就有了她 tacit 的同意 — she never said 'yes, go ahead'她從來沒說過「好，去吧」, but her silence has done the work of a yes但她的沉默已經做了「好」這個字該做的事。

The important part is that tacit does not just mean 'unspoken'. It means unspoken AND understood by both sides. Something can be silent and mean nothing; tacit means the silence itself carries the message.

The important part is that tacit does not just mean 'unspoken'重要的是，tacit 不只是「沒說出口」的意思。It means unspoken AND understood by both sides它的意思是「沒說出口」而且「雙方都懂」。Something can be silent and mean nothing有些沉默什麼意義都沒有; tacit means the silence itself carries the message但 tacit 指的是這個沉默本身就在傳達訊息。

That is why it goes so naturally with a small set of nouns: tacit agreement, tacit approval, tacit understanding, tacit support, tacit consent, tacit admission. You will meet it in those phrases far more often than anywhere else — it is not a word people spread freely over other nouns. It feels formal and a little cool.

That is why it goes so naturally with a small set of nouns這就是為什麼它總是跟一小群名詞很自然地搭在一起: tacit agreement, tacit approval, tacit understanding, tacit support, tacit consent, tacit admission像 tacit agreement（默契）、tacit approval（默許）、tacit understanding（心照不宣的了解）、tacit support（默默的支持）、tacit consent（默許）、tacit admission（默認）。You will meet it in those phrases far more often than anywhere else你會在這些固定搭配裡遇到它的頻率遠高於其他地方 — it is not a word people spread freely over other nouns人們不會隨便把它套在別的名詞上。It feels formal and a little cool它給人的感覺是正式，而且有點冷。

You read it in newspapers, in law, in business writing, in academic work. Two friends will not say 'we had a tacit agreement'; they will say 'we just kind of knew'. When a journalist writes that a government gave tacit support to something, there is often a quiet edge to it — the suggestion that the support was deliberately left unspoken so that nobody could be held responsible for it later.

You read it in newspapers, in law, in business writing, in academic work你會在報紙、法律、商業文件和學術著作裡讀到它。Two friends will not say 'we had a tacit agreement'兩個朋友不會說「we had a tacit agreement」; they will say 'we just kind of knew'他們會說「we just kind of knew」（我們就是心裡有數）。When a journalist writes that a government gave tacit support to something當記者寫到某個政府對某件事給予 tacit 的支持, there is often a quiet edge to it這句話裡常常帶著一點微妙的言外之意 — the suggestion that the support was deliberately left unspoken暗示這份支持是刻意不說出口的 so that nobody could be held responsible for it later這樣以後才沒有人需要為此負責。

There is one place where it stretches beyond agreements: 'tacit knowledge' — the things an experienced person knows how to do but cannot explain in words, like how a good cook knows when the oil is hot enough. That use comes from philosophy and business writing and is now fairly common. Only the adjective form exists; there is no verb.

There is one place where it stretches beyond agreements有一個地方它的用法超出了「協議」這個範圍: 'tacit knowledge'就是「tacit knowledge」（內隱知識） — the things an experienced person knows how to do but cannot explain in words指的是一個有經驗的人知道怎麼做，卻沒辦法用言語解釋清楚的東西, like how a good cook knows when the oil is hot enough像是一個好廚師怎麼知道油夠熱了。That use comes from philosophy and business writing這種用法源自哲學和商業寫作 and is now fairly common現在已經相當常見。Only the adjective form exists只有形容詞這個詞性存在; there is no verb沒有動詞形式。